Substituted tetracycline compounds for treatment of inflammatory skin disorders

ABSTRACT

Methods and compositions for the treatment of skin disorders (e.g., acne, rosacea) are described.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 60/876,434, filed Dec. 21, 2006. The contents of the foregoingapplication are hereby incorporated in their entirety.

BACKGROUND OF THE INVENTION

Acne is a disorder resulting from the actions of hormones on thesebaceous glands, which leads to plugged pores and outbreaks of lesions,commonly called pimples. Nearly 17 million people in the United Stateshave acne, making it the most common skin disease. Severe acne can leadto disfiguring, permanent scarring.

Acne is described as a disorder of the pilosebaceous units (PSUs). Foundover most of the body, PSUs consist of a sebaceous gland connected to acanal, called a follicle that contains a fine hair. These units are mostnumerous on the face, upper back and chest. The sebaceous glands make anoily substance called sebum that normally empties onto the skin surfacethrough the opening of the follicle, also called a pore. Cells calledkeratinocytes line the follicle.

The hair, sebum and keratinocytes that fill the narrow follicle mayproduce a plug, which is an early sign of acne. The plug prevents sebumfrom reaching the surface of the skin through a pore. The mixture of oiland cells allows bacteria Propionibacterium acnes (P. acnes) thatnormally live on the skin to grow in the plugged follicles. The bacteriaproduce chemicals and enzymes and attract white blood cells that causeinflammation. Then the wall of the plugged follicle breaks down, thesebum, shed skin cells and bacteria disseminate into the nearby tissues,leading to lesions or pimples.

For patients with moderate to severe acne, the doctor often prescribesoral antibiotics. Oral antibiotics are thought to help control acne bycurbing the growth of bacteria and reducing inflammation. Tetracyclineshave been used because of their anti-bacterial and anti-inflammatoryproperties.

SUMMARY OF THE INVENTION

In one embodiment, the present invention pertains, at least in part, toa method for treating an inflammatory skin disorder in a subject byadministering an effective amount of a substituted tetracycline compoundto the subject. Advantageously, the substituted tetracycline compoundsused in the methods of the invention have one or more of the followingcharacteristics: 1) narrow spectrum anti-bacterial activity againstgram-positive bacteria; 2) anti-inflammatory activity; 3) lessphototoxicity than doxycycline; and 4) oxidatively more stability thanminocycline.

In another embodiment, the present invention pertains, at least in part,to a method of treating an inflammatory skin disorder in a subject byadministering an effective amount of a substituted tetracycline compoundof formula I:

wherein

X is CHC(R¹³Y′Y), CR^(6′)R⁶, C═CR^(6′)R⁶, S, NR⁶ or O;

E is NR^(7d)R^(7e), OR^(7f), or (CH₂)₀₋₁C(═W′)WR^(7g);

W is O, S, NR^(7h), or CR^(7i)R^(7j);

W′ is O, S, or NR^(7k);

R², R^(2′), R^(4′), R^(4a) and R^(4b) are each independently hydrogen,alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylsulfinyl,alkylsulfonyl, alkylamino, arylalkyl, aryl, heterocyclic, heteroaromaticor a prodrug moiety;

R³, R¹⁰, R¹¹ and R¹² are each hydrogen or a prodrug moiety;

R⁴ is NR^(4a)R^(4b), alkyl, alkenyl, alkynyl, hydroxyl, halogen, orhydrogen;

R⁵ and R^(5′) are each independently hydroxyl, hydrogen, thiol,alkanoyl, aroyl, alkaroyl, aryl, heteroaromatic, alkyl, alkenyl,alkynyl, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino,arylalkyl, alkyl carbonyloxy, or aryl carbonyloxy;

R⁶ and R^(6′) are each independently hydrogen, methylene, absent,hydroxyl, halogen, thiol, alkyl, alkenyl, alkynyl, aryl, alkoxy,alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl;

R^(7a), R^(7b), R^(7c), R^(7d), R^(7e), R^(7f), R^(7g), R^(7h), R^(7i),R^(7k) and R^(7j) are each independently hydrogen, allyl, alkyl,alkenyl, alkynyl, hydroxyl, alkoxy, alkylthio, alkylsulfinyl,alkylsulfonyl, amino, alkylamino, aminoalkyl, acyl, aryl, arylalkyl,alkylcarbonyloxy, or arylcarbonyloxy, or R^(7c) and R^(7d) or R^(7c) andR^(7f) are linked to form a ring;

R⁸ is hydrogen, hydroxyl, halogen, thiol, alkyl, alkenyl, alkynyl, aryl,alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, or anarylalkyl;

R⁹ is hydrogen, nitro, alkyl, alkenyl, alkynyl, aryl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, arylalkyl, amino, aminoalkyl, amido,arylalkenyl, arylalkynyl, thionitroso, or—(CH₂)₀₋₃(NR^(9c))₀₋₁C(═Z′)ZR^(9a);

Z is CR^(9d)R^(9e), S, NR^(9b) or O;

Z′ is O, S, or NR^(9f);

R^(9a), R^(9b), R^(9c), R^(9d), R^(9e) and R^(9f) are each independentlyhydrogen, acyl, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, arylalkyl, aryl, heterocyclic,heteroaromatic or a prodrug moiety;

R¹³ is hydrogen, hydroxy, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl; and

Y′ and Y are each independently hydrogen, halogen, hydroxyl, cyano,sulfhydryl, amino, amido, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl, andpharmaceutically acceptable salts thereof.

The invention also pertains, at least in part, to a method of treatingan inflammatory skin disorder in a subject by administering an effectiveamount of a substituted tetracycline compound of formula II:

wherein

X is CHC(R¹³Y′Y), CR^(6′)R⁶, C═CR^(6′)R⁶, S, NR⁶ or O;

J is NR^(7m)R^(7n), OR^(7o), or heteroaryl;

R², R^(2′), R^(4a), R^(4b) are each independently hydrogen, alkyl,alkenyl, alkynyl, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl,alkylamino, arylalkyl, aryl, heterocyclic, heteroaromatic or a prodrugmoiety;

R³, R¹⁰, R¹¹ and R¹² are each hydrogen or a prodrug moiety;

R⁴ is NR^(4a)R^(4b), alkyl, alkenyl, alkynyl, hydroxyl, halogen, orhydrogen;

R⁵ and R^(5′) are each independently hydroxyl, hydrogen, thiol,alkanoyl, aroyl, alkaroyl, aryl, heteroaromatic, alkyl, alkenyl,alkynyl, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino,arylalkyl, alkyl carbonyloxy, or aryl carbonyloxy;

R⁶ and R^(6′) are each independently hydrogen, methylene, absent,hydroxyl, halogen, thiol, alkyl, alkenyl, alkynyl, aryl, alkoxy,alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl;

R^(7l), R^(7m), R^(7n), and R^(7o) are each independently hydrogen,alkyl, alkenyl, alkynyl, hydroxyl, alkoxy, amino, alkylamino,aminoalkyl, acyl, alkylthio, alkylsulfinyl,

R⁸ is hydrogen, hydroxyl, halogen, thiol, alkyl, alkenyl, alkynyl, aryl,alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, or anarylalkyl;

R⁹ is hydrogen, nitro, alkyl, alkenyl, alkynyl, aryl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, arylalkyl, amino, aminoalkyl, amido,arylalkenyl, arylalkynyl, thionitroso or—(CH₂)₀₋₃(NR^(9c))₀₋₁C(═Z′)ZR^(9a);

Z is CR^(9d)R^(9e), S, NR^(9b) or O;

Z′ is O, S, or NR^(9f);

R^(9a), R^(9b), R^(9c), R^(9d), R^(9e) and R^(9f) are each independentlyhydrogen, acyl, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, arylalkyl, aryl, heterocyclic,heteroaromatic or a prodrug moiety;

R¹³ is hydrogen, hydroxy, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl; and

Y′ and Y are each independently hydrogen, halogen, hydroxyl, cyano,sulfhydryl, amino, amido, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl, andpharmaceutically acceptable salts thereof.

In yet another embodiment, the invention pertains, at least in part, toa method for treating an inflammatory skin disorder in a subject byadministering to the subject an effective amount of a substitutedtetracycline compound of formula III:

wherein

X is CHC(R¹³Y′Y), CR^(6′)R⁶, C═CR^(6′)R⁶, S, NR⁶, or O;

R², R^(2′), R^(4′), R^(4a) and R^(4b) are each independently hydrogen,alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylsulfinyl,alkylsulfonyl, alkylamino, arylalkyl, aryl, heterocyclic, heteroaromaticor a prodrug moiety;

R³, R¹¹ and R¹² are each hydrogen or a prodrug moiety;

R⁴ is NR^(4a)R^(4b), alkyl, alkenyl, alkynyl, hydroxyl, halogen, orhydrogen;

R⁵ and R^(5′) are each independently hydroxyl, hydrogen, thiol,alkanoyl, aroyl, alkaroyl, aryl, heteroaromatic, alkyl, alkenyl,alkynyl, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino,arylalkyl, alkyl carbonyloxy, or aryl carbonyloxy;

R⁶ and R^(6′) are each independently hydrogen, methylene, absent,hydroxyl, halogen, thiol, alkyl, alkenyl, alkynyl, aryl, alkoxy,alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl;

R^(7p) is hydrogen, alkyl, alkenyl, alkynyl, hydroxyl, alkoxy,alkylthio, alkylsulfinyl, alkylsulfonyl, amino, aminoalkyl, alkylamino,aryl, acyl, arylalkyl, alkyl carbonyloxy, or arylcarbonyloxy;

R⁸ is hydrogen, hydroxyl, halogen, thiol, alkyl, alkenyl, alkynyl, aryl,alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, or anarylalkyl;

R⁹ is hydrogen, nitro, alkyl, alkenyl, alkynyl, aryl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, arylalkyl, amino, aminoalkyl, amido,arylalkenyl, arylalkynyl, thionitroso or—(CH₂)₀₋₃(NR^(9c))₀₋₁C(═Z′)ZR^(9a);

Z is CR^(9d)R^(9e), S, NR^(9b) or O;

Z′ is O, S, or NR^(9f);

R^(9a), R^(9b), R^(9c), R^(9d), R^(9e) and R^(9f) are each independentlyhydrogen, acyl, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, arylalkyl, aryl, heterocyclic,heteroaromatic or a prodrug moiety;

R^(10a) is hydrogen;

R¹³ is hydrogen, hydroxy, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl; and

Y′ and Y are each independently hydrogen, halogen, hydroxyl, cyano,sulfhydryl, amino, amido, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl, andpharmaceutically acceptable salts thereof.

In one embodiment, the present invention pertains, at least in part, toa method for treating an inflammatory skin disorder in a subject byadministering to the subject an effective amount of a substitutedtetracycline compound of formula IV:

wherein

X is CHC(R¹³Y′Y), CR^(6′)R⁶, C═CR^(6′)R⁶, S, NR⁶, or O;

R², R^(2′), R^(4′), R^(4a) and R^(4b) are each independently hydrogen,alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylsulfinyl,alkylsulfonyl, alkylamino, arylalkyl, aryl, heterocyclic, heteroaromaticor a prodrug moiety;

R³, R¹⁰, R¹¹ and R¹² are each hydrogen or a pro-drug moiety;

R⁴ is NR^(4a)R^(4b), alkyl, alkenyl, alkynyl, hydroxyl, halogen, orhydrogen;

R⁵ and R^(5′) are each independently hydroxyl, hydrogen, thiol,alkanoyl, aroyl, alkaroyl, aryl, heteroaromatic, alkyl, alkenyl,alkynyl, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino,arylalkyl, alkyl carbonyloxy, or aryl carbonyloxy;

R⁶ and R^(6′) are each independently hydrogen, methylene, absent,hydroxyl, halogen, thiol, alkyl, alkenyl, alkynyl, aryl, alkoxy,alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl;

R^(7q) is heteroaryl;

R⁸ is hydrogen, hydroxyl, halogen, thiol, alkyl, alkenyl, alkynyl, aryl,alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, or anarylalkyl;

R⁹ is hydrogen, nitro, alkyl, alkenyl, alkynyl, aryl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, arylalkyl, amino, aminoalkyl, amido,arylalkenyl, arylalkynyl, thionitroso or—(CH₂)₀₋₃(NR^(9c))₀₋₁C(═Z′)ZR^(9a);

Z is CR^(9d)R^(9e), S, NR^(9b) or O;

Z′ is O, S, or NR^(9f);

R^(9a), R^(9b), R^(9c), R^(9d), R^(9e) and R^(9f) are each independentlyhydrogen, acyl, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, arylalkyl, aryl, heterocyclic,heteroaromatic or a prodrug moiety;

R¹³ is hydrogen, hydroxy, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl; and

Y′ and Y are each independently hydrogen, halogen, hydroxyl, cyano,sulfhydryl, amino, amido, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl, andpharmaceutically acceptable salts thereof.

In yet another embodiment, the present invention pertains, at least inpart, to a method of treating an inflammatory skin disorder in a subjectby administering to the subject an effective amount of a substitutedtetracycline compound of formula V:

wherein

X is CHC(R¹³Y′Y), CR^(6′)R⁶, C═CR^(6′)R⁶, S, NR⁶, or O;

R², R^(2′), R^(4′), R^(4a) and R^(4b) are each independently hydrogen,alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylsulfinyl,alkylsulfonyl, alkylamino, arylalkyl, aryl, heterocyclic, heteroaromaticor a prodrug moiety;

R³, R¹⁰, R¹¹ and R¹² are each hydrogen or a pro-drug moiety;

R⁴ is NR^(4a)R^(4b), alkyl, alkenyl, alkynyl, hydroxyl, halogen, orhydrogen;

R⁵ and R^(5′) are each independently hydroxyl, hydrogen, thiol,alkanoyl, aroyl, alkaroyl, aryl, heteroaromatic, alkyl, alkenyl,alkynyl, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino,arylalkyl, alkyl carbonyloxy, or aryl carbonyloxy;

R⁶ and R^(6′) are each independently hydrogen, methylene, absent,hydroxyl, halogen, thiol, alkyl, alkenyl, alkynyl, aryl, alkoxy,alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl;

R^(7r) is hydrogen, alkyl, alkenyl, alkynyl, hydroxyl, alkoxy, amino,alkylamino, aminoalkyl, acyl, alkylthio, alkylsulfinyl, alkylsulfonyl,aryl, arylalkyl, alkylcarbonyloxy, or arylcarbonyloxy;

R⁸ is hydrogen, hydroxyl, halogen, thiol, alkyl, alkenyl, alkynyl, aryl,alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, or anarylalkyl;

R^(9x) is CN, CR^(9g)NR^(9h) or CR^(9i)R^(9j)NR^(9k)R^(9l);

R^(9g), R^(9h), R^(9i), R^(9j), R^(9k) and R^(9l) are each independentlyhydrogen, alkyl, alkenyl, alkynyl, hydroxyl, alkoxy, amino, alkylamino,aminoalkyl, acyl, alkylthio, alkylsulfinyl, alkylsulfonyl, aryl,arylalkyl, alkylcarbonyloxy, or arylcarbonyloxy;

R¹³ is hydrogen, hydroxy, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl; and

Y′ and Y are each independently hydrogen, halogen, hydroxyl, cyano,sulfhydryl, amino, amido, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl, andpharmaceutically acceptable salts thereof.

In another embodiment, the present invention pertains, at least in part,to a method for treating an inflammatory skin disorder in a subject byadministering an effective amount of a substituted tetracycline compoundof formula VI:

wherein

X is CHC(R¹³Y′Y), CR^(6′)R⁶, C═CR^(6′)R⁶, S, NR⁶, or O;

p is a single bond or a double bond;

Q is CR^(7s) when p is a double bond or Q is CR^(7s′)R^(7s″) when p is asingle bond;

R², R^(2′), R^(4′), R^(4a) and R^(4b) are each independently hydrogen,alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylsulfinyl,alkylsulfonyl, alkylamino, arylalkyl, aryl, heterocyclic, heteroaromaticor a prodrug moiety;

R³, R¹⁰, R¹¹ and R¹² are each hydrogen or a pro-drug moiety;

R⁴ is NR^(4a)R^(4b), alkyl, alkenyl, alkynyl, hydroxyl, halogen, orhydrogen;

R⁵ and R^(5′) are each independently hydroxyl, hydrogen, thiol,alkanoyl, aroyl, alkaroyl, aryl, heteroaromatic, alkyl, alkenyl,alkynyl, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino,arylalkyl, alkyl carbonyloxy, or aryl carbonyloxy;

R⁶ and R^(6′) are each independently hydrogen, methylene, absent,hydroxyl, halogen, thiol, alkyl, alkenyl, alkynyl, aryl, alkoxy,alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl;

R^(7s), R^(7s′) and R^(7s″) are each hydrogen, alkyl, alkenyl, alkynyl,hydroxyl, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, amino,aminoalkyl, alkylamino, aryl, acyl, arylalkyl, alkyl carbonyloxy, orarylcarbonyloxy;

R⁸ is hydrogen, hydroxyl, halogen, thiol, alkyl, alkenyl, alkynyl, aryl,alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, or anarylalkyl;

R⁹ is hydrogen, nitro, alkyl, alkenyl, alkynyl, aryl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, arylalkyl, amino, aminoalkyl, amido,arylalkenyl, arylalkynyl, thionitroso or—(CH₂)₀₋₃(NR^(9c))₀₋₁C(═Z′)ZR^(9a);

Z is CR^(9d)R^(9e), S, NR^(9b) or O;

Z′ is O, S, or NR^(9f);

R^(9a), R^(9b), R^(9c), R^(9d), R^(9e) and R^(9f) are each independentlyhydrogen, acyl, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, arylalkyl, aryl, heterocyclic,heteroaromatic or a prodrug moiety;

R¹³ is hydrogen, hydroxy, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl; and

Y′ and Y are each independently hydrogen, halogen, hydroxyl, cyano,sulfhydryl, amino, amido, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl, andpharmaceutically acceptable salts thereof.

The invention also pertains, at least in part, to a pharmaceuticalcomposition comprising a pharmaceutically acceptable carrier and aneffective amount of a substituted tetracycline compound for thetreatment of an inflammatory skin disorder, wherein said compound is offormula I, II, III, IV, V or VI.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graphical comparison of the modulation of carrageenaninduced inflammation in the rat paw edema model between doxycycline andcompound A.

FIG. 2 is a graphical comparison of the modulation of carregeenaninduced inflammation in the rat paw edema model between minocycline andcompound P.

DETAILED DESCRIPTION OF THE INVENTION

In one embodiment, the present invention is directed to a method fortreating an inflammatory skin disorder in a subject by administering aneffective amount of a substituted tetracycline compound to the subject.Advantageously, the tetracycline compound used in the methods of theinvention has one or more of the following characteristics: 1) narrowspectrum anti-bacterial activity against gram-positive bacteria; 2)anti-inflammatory activity; 3) a phototoxicity less than or equal todoxycycline; and 4) an oxidative potential less than or equal tominocycline.

The term “inflammatory skin disorder” includes, for example, eczema,dermatitis, psoriasis, pyoderma gangrenosum, acne and rosacea.

The term “subject” includes animals (e.g., mammals, e.g., cats, dogs,horses, pigs, cows, sheep, rodents, rabbits, squirrels, bears, primates(e.g., chimpanzees, gorillas, and humans)) which are capable of (orcurrently) suffering from an inflammatory skin disorder. It alsoincludes transgenic animal models.

The term “treated,” “treating” or “treatment” includes therapeuticand/or prophylactic treatment of inflammatory skin disorders. Thetreatment includes the diminishment or alleviation of at least onesymptom associated with an inflammatory skin disorder. For example,treatment can be diminishment of one or several symptoms of theinflammatory skin disorder or complete eradication of the inflammatoryskin disorder.

The language “effective amount” of the tetracycline compound is thatamount necessary or sufficient to treat or prevent the inflammatory skindisorder in a subject, e.g. prevent the various symptoms of theinflammatory skin disorder. The effective amount can vary depending onsuch factors as the size and weight of the subject, the type ofinflammatory skin disorder, or the particular tetracycline compound. Forexample, the choice of the tetracycline compound can affect whatconstitutes an “effective amount.” One of ordinary skill in the artwould be able to study the aforementioned factors and make thedetermination regarding the effective amount of the tetracyclinecompound without undue experimentation.

The term “tetracycline compound” includes substituted tetracyclinecompounds or compounds with a similar ring structure to tetracycline.Examples of tetracycline compounds include: chlortetracycline,oxytetracycline, demeclocycline, methacycline, sancycline, chelocardin,rolitetracycline, lymecycline, apicycline; clomocycline, guamecycline,meglucycline, mepylcycline, penimepicycline, pipacycline, etamocycline,penimocycline, etc. Other derivatives and analogues comprising a similarfour ring structure are also included (See Rogalski, “ChemicalModifications of Tetracyclines,” the entire contents of which are herebyincorporated herein by reference). Table 1 depicts tetracycline andseveral known other tetracycline derivatives.

TABLE 1

Oxytetracycline

Demeclocycline

Minocycline

Methacycline

Doxycycline

Chlortetracycline

Tetracycline

Sancycline

Chelocardin

Other tetracycline compounds which may be modified using the methods ofthe invention include, but are not limited to,6-demethyl-6-deoxy-4-dedimethylaminotetracycline; tetracyclino-pyrazole;7-chloro-4-dedimethylaminotetracycline;4-hydroxy-4-dedimethylaminotetracycline;12α-deoxy-4-dedimethylaminotetracycline;5-hydroxy-6α-deoxy-4-dedimethylaminotetracycline;4-dedimethylamino-12α-deoxyanhydrotetracycline;7-dimethylamino-6-demethyl-6-deoxy-4-dedimethylaminotetracycline;tetracyclinonitrile; 4-oxo-4-dedimethylaminotetracycline 4,6-hemiketal;4-oxo-11a C1-4-dedimethylaminotetracycline-4,6-hemiketal;5a,6-anhydro-4-hydrazon-4-dedimethylamino tetracycline;4-hydroxyimino-4-dedimethylamino tetracyclines;4-hydroxyimino-4-dedimethylamino 5a,6-anhydrotetracyclines;4-amino-4-dedimethylamino-5a,6 anhydrotetracycline;4-methylamino-4-dedimethylamino tetracycline;4-hydrazono-11a-chloro-6-deoxy-6-demethyl-6-methylene-4-dedimethylaminotetracycline; tetracycline quaternary ammonium compounds;anhydrotetracycline betaines; 4-hydroxy-6-methyl pretetramides; 4-ketotetracyclines; 5-keto tetracyclines; 5a,11a dehydro tetracyclines; 11aC1-6, 12 hemiketal tetracyclines; 11a C1-6-methylene tetracyclines; 6,13diol tetracyclines; 6-benzylthiomethylene tetracyclines;7,11a-dichloro-6-fluoro-methyl-6-deoxy tetracyclines; 6-fluoro(α)-6-demethyl-6-deoxy tetracyclines; 6-fluoro (β)-6-demethyl-6-deoxytetracyclines; 6-αacetoxy-6-demethyl tetracyclines; 6-βacetoxy-6-demethyl tetracyclines; 7,13-epithiotetracyclines;oxytetracyclines; pyrazolotetracyclines; 11a halogens of tetracyclines;12a formyl and other esters of tetracyclines; 5,12a esters oftetracyclines; 10,12a-diesters of tetracyclines; isotetracycline;12-a-deoxyanhydro tetracyclines;6-demethyl-12a-deoxy-7-chloroanhydrotetracyclines; B-nortetracyclines;7-methoxy-6-demethyl-6-deoxytetracyclines;6-demethyl-6-deoxy-5a-epitetracyclines; 8-hydroxy-6-demethyl-6-deoxytetracyclines; monardene; chromocycline; 5a methyl-6-demethyl-6-deoxytetracyclines; 6-oxa tetracyclines, and 6 thia tetracyclines.

The term “substituted tetracycline compound” includes tetracyclinecompounds with one or more additional substituents, e.g., at the 1, 2,3, 4, 5, 6, 7, 8, 9, 10, 11, 11a, 12, 12a or 13 position or at any otherposition which allows the substituted tetracycline compound of theinvention to perform its intended function, e.g., treat a skin disorder.Preferably, the substituted tetracycline compounds of the invention arecompounds of formula I, II, III, IV, V or VI. It does not includeunsubstituted minocycline, unsubstituted doxycycline or sancycline.

In one embodiment, the substituted tetracycline compound has an MIC(e.g., as measured in Example 2) of between about 0.001 to 64 μg/mL,preferably between about 0.001 and 16 μg/mL and more preferably betweenabout 0.001 and 4 μg/mL.

In one embodiment, the substituted tetracycline compound exhibitsantibacterial activity. In another embodiment, the substitutedtetracycline compound exhibits anti-inflammatory activity. In yetanother embodiment, the substituted tetracycline compound exhibits bothantibacterial and anti-inflammatory activities. The term“anti-inflammatory activity” includes activity that prevents, reduces orameliorates the symptoms of acute or chronic inflammation. Thesubstituted tetracycline compounds of the invention may treat, prevent,reduce or ameliorate the symptoms of inflammation (e.g., redness,swelling, heat, pain, loss of function, tissue destruction, etc.) and/ormay effect the biochemical pathways that cause inflammation in the bodyto treat, prevent, reduce or ameliorate inflammation.

In a further embodiment, the substituted tetracycline compounds of theinvention may have one or more; two or more; three or more; or all ofthe following characteristics: 1) narrow spectrum anti-bacterialactivity; 2) anti-inflammatory activity; 3) a phototoxicity less than orequal to doxycycline and 4) an oxidative potential less than or equal tominocycline.

In a further embodiment, the substituted tetracycline compound may havenarrow spectrum antibiotic activity. The term “narrow spectrum” includesactivity against specific types of bacteria. In one embodiment, thesubstituted tetracycline compounds exhibit greater antibacterialactivity against gram positive bacteria than against gram negativebacteria. Examples of gram positive bacteria include, for example, S.aureus, S. pneumoniae, P. granulosum and P. acnes.

In one embodiment, the substituted tetracycline compound used in themethods of the invention has an MIC of less than about 64 μg/mL, lessthan about 32 μg/mL, less than about 16 μg/mL, less than about 8 μg/mL,less than about 4 μg/mL or less than about 1 μg/mL against gram positivebacteria, e.g., P. acnes, and/or P. granulosum.

In one embodiment, the substituted tetracycline compound used in themethods of the invention has a minimum inhibitory concentration (MIC)less than that of doxycycline or minocycline for S. aureus, P.granulosum, S. pneumoniae, or P. acnes.

In another embodiment, the tetracycline compounds of the invention havenarrow spectrum antibacterial activity. The term “narrow spectrum”includes tetracycline compounds which do have substantial antibacterialactivity against gram positive bacteria, e.g., tetracycline compoundswith an MIC of less than about 64 μg/mL, less than about 32 μg/mL, lessthan about 16 μg/mL, less than about 8 μg/mL, less than about 4 μg/mL orless than about 1 μg/mL against S. aureus, P. granulosum, P. acnes or S.pneumoniae (e.g., as tested in the assay described in Example 2).

The term “narrow spectrum” includes tetracycline compounds which do nothave substantial antibacterial activity against gram negative bacteria,e.g., tetracycline compounds with an MIC of greater than about 1 μg/mL,greater than about 4 μg/mL, greater than about 8 μg/mL, greater thanabout 16 μg/mL, greater than about 32 μg/mL, or greater than about 64μg/mL against gram negative bacteria such as E. coli or B.thetaiotaomicron (e.g., as tested in the assay described in Example 2).

In another embodiment, the substituted tetracycline compounds used inthe methods of the invention has anti-inflamatory activity, e.g., asdetermined in the rat-paw edema model described in Example 7.

In another embodiment, the substituted tetracycline compounds used inthe methods of the invention have a phototoxicity equal to or less thanthat of doxycycline (e.g., such as measured in the assay described inExample 4). In yet another embodiment, the substituted tetracyclinecompounds used in the methods of the invention have an oxidativepotential less than or equal to the oxidative potential of minocycline(e.g., such as measured in the assay described in Example 5).

In one embodiment, the substituted tetracycline compound of theinvention is of the formula I:

wherein

X is CHC(R¹³Y′Y), CR^(6′)R⁶, C═CR^(6′)R⁶, S, NR⁶, or O;

E is NR^(7d)R^(7e), OR^(7f), or (CH₂)₀₋₁C(═W′)WR^(7g);

W is O, S, NR^(7h), or CR^(7i)R^(7j);

W′ is O, S, or NR^(7k);

R², R^(2′), R^(4′), R^(4a) and R^(4b) are each independently hydrogen,alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylsulfinyl,alkylsulfonyl, alkylamino, arylalkyl, aryl, heterocyclic, heteroaromaticor a prodrug moiety;

R³, R¹⁰, R¹¹ and R¹² are each hydrogen or a prodrug moiety;

R⁴ is NR^(4a)R^(4b), alkyl, alkenyl, alkynyl, hydroxyl, halogen, orhydrogen;

R⁵ and R^(5′) are each independently hydroxyl, hydrogen, thiol,alkanoyl, aroyl, alkaroyl, aryl, heteroaromatic, alkyl, alkenyl,alkynyl, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino,arylalkyl, alkyl carbonyloxy, or aryl carbonyloxy;

R⁶ and R^(6′) are each independently hydrogen, methylene, absent,hydroxyl, halogen, thiol, alkyl, alkenyl, alkynyl, aryl, alkoxy,alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl;

R^(7a), R^(7b), R^(7c), R^(7d), R^(7e), R^(7f), R^(7g), R^(7h), R^(7i),R^(7k) and R^(7j) are each independently hydrogen, allyl, alkyl,alkenyl, alkynyl, hydroxyl, alkoxy, alkylthio, alkylsulfinyl,alkylsulfonyl, amino, alkylamino, aminoalkyl, acyl, aryl, arylalkyl,alkylcarbonyloxy, or arylcarbonyloxy, or R^(7c) and R^(7d) or R^(7c) andR^(7f) are linked to form a ring;

R⁸ is hydrogen, hydroxyl, halogen, thiol, alkyl, alkenyl, alkynyl, aryl,alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, or anarylalkyl;

R⁹ is hydrogen, nitro, alkyl, alkenyl, alkynyl, aryl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, arylalkyl, amino, aminoalkyl, amido,arylalkenyl, arylalkynyl, thionitroso, or—(CH₂)₀₋₃(NR^(9c))₀₋₁C(═Z′)ZR^(9a);

Z is CR^(9d)R^(9e), S, NR^(9b) or O;

Z′ is O, S, or NR^(9f);

R^(9a), R^(9b), R^(9c), R^(9d), R^(9e) and R^(9f) are each independentlyhydrogen, acyl, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, arylalkyl, aryl, heterocyclic,heteroaromatic or a prodrug moiety;

R¹³ is hydrogen, hydroxy, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl; and

Y′ and Y are each independently hydrogen, halogen, hydroxyl, cyano,sulfhydryl, amino, amido, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl, andpharmaceutically acceptable salts thereof.

In one embodiment, X is CR^(6′)R⁶, R⁴ is NR^(4a)R^(4b), R^(4a) andR^(4b) are each alkyl (e.g., methyl); R², R^(2′), R³, R^(4′) R⁵, R^(5′)R⁶, R^(6′), R^(7a), R^(7b), R^(7c), R⁸, R⁹, R¹⁰, R¹¹ and R¹² are eachhydrogen; E is OR^(7f); R^(7f) is allyl (e.g., CH₂═CHCH₂—) or alkyl(e.g., ethyl; isopropyl; t-butyl; alkoxy substituted alkyl (e.g.,methoxyethyl); halogen substituted alkyl (e.g., alkyl substituted withfluorine, for example, FCH₂CH₂—; F₂CHCH₂—; CF₃CH₂— or CF₂H—);alkylcarbonylalkyl (e.g., CH₃CO(CH₂)_(n)—, in which m is an integer from0-6, for example 1); alkoxycarbonylalkyl (e.g., CH₃OCO(CH₂)_(m)—, inwhich m is an integer from 0-6, for example 1) or carboxylatealkyl(HOOC(CH₂)_(q)—, in which q is an integer from 0-6, for example 1).

In one embodiment, X is CR^(6′)R⁶, R⁴ is NR^(4a)R^(4b), R^(4a) andR^(4b) are each alkyl (e.g., methyl); R², R^(2′), R³, R^(4′), R⁵, R^(5′)R⁶, R^(6′), R^(7a), R^(7b), R⁸, R⁹, R¹⁰, R¹¹ and R¹² are each hydrogen;E is OR^(7f) and R^(7c) and R^(7f) are linked to join a ring, forexample, a 5- or 6-membered ring

In another embodiment, X is CR^(6′)R⁶, R⁴ is NR^(4a)R^(4b), R^(4a) andR^(4b) are each alkyl (e.g., methyl); R², R^(2′), R³, R^(4′) R⁵, R^(5′)R⁶, R^(6′), R^(7a), R^(7b)R⁸, R⁹, R¹⁰, R¹¹ and R¹² are each hydrogen; Eis OR^(7f); R^(7c) and R^(7f) may be each independently alkyl (e.g.,methyl or ethyl).

In yet another embodiment, X is CR^(6′)R⁶, R⁴ is NR^(4a)R^(4b), R^(4a)and R^(4b) are each alkyl (e.g., methyl); R², R^(2′), R³, R^(4′) R⁵,R^(5′), R⁶, R^(6′), R^(7a), R^(7b), R^(7c), R⁸, R⁹, R¹⁰, R¹¹ and R¹² areeach hydrogen; E is NR^(7d)R^(7e); R^(7c) is alkyl (e.g., ethyl); R^(7d)is hydrogen and R^(7e) is alkyl (e.g., ethyl).

In another embodiment, X is CR^(6′)R⁶, R⁴ is NR^(4a)R^(4b), R^(4a) andR^(4b) are each alkyl (e.g., methyl); R², R^(2′), R³, R^(4′) R⁵, R^(5′)R⁶, R^(6′) R^(7a), R^(7b), R^(7c), R⁸, R⁹, R¹⁰, R¹¹ and R¹² are eachhydrogen; E is —C(═W′)WR^(7g); W and W′ are each oxygen; R^(7c) is allyl(e.g., CH₂═CHCH₂—) and R^(7g) is alkoxy (e.g., methoxy).

In one embodiment, X is CR^(6′)R⁶R⁴ is NR^(4a)R^(4b), R^(4a) and R^(4b)are each alkyl (e.g., methyl); R², R^(2′), R³, R^(4′) R⁵, R^(5′) R⁶,R^(6′), R^(7a), R^(7b), R^(7c), R⁸, R⁹, R¹⁰, R¹¹ and R¹² are eachhydrogen; E is —CH₂(C═W′)WR^(7g); R^(7c) is alkyl (e.g., methyl); W isCR^(7i)R^(7j); R^(7i), R^(7j) and R^(7g) are each hydrogen; W′ isNR^(7k) and R^(7k) is alkoxy (e.g., ethoxy).

Examples of substituted tetracycline compounds of formula I include, forexample:

and pharmaceutically acceptable salts thereof.

In another embodiment, the substituted tetracycline compound of theinvention is a compound of formula II:

wherein

X is CHC(R¹³Y′Y), CR^(6′)R⁶, C═CR^(6′)R⁶, S, NR⁶ or O;

J is NR^(7m)R^(7n), OR^(7o) or heteroaryl;

R², R^(2′), R^(4′), R^(4a) and R^(4b) are each independently hydrogen,alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylsulfinyl,alkylsulfonyl, alkylamino, arylalkyl, aryl, heterocyclic, heteroaromaticor a prodrug moiety;

R³, R¹⁰, R¹¹ and R¹² are each hydrogen or a prodrug moiety;

R⁴ is NR^(4a)R^(4b), alkyl, alkenyl, alkynyl, hydroxyl, halogen, orhydrogen;

R⁵ and R^(5′) are each independently hydroxyl, hydrogen, thiol,alkanoyl, aroyl, alkaroyl, aryl, heteroaromatic, alkyl, alkenyl,alkynyl, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino,arylalkyl, alkyl carbonyloxy, or aryl carbonyloxy;

R⁶ and R^(6′) are each independently hydrogen, methylene, absent,hydroxyl, halogen, thiol, alkyl, alkenyl, alkynyl, aryl, alkoxy,alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl;

R^(7l), R^(7m), R^(7n) and R^(7o) are each independently hydrogen,alkyl, alkenyl, alkynyl, hydroxyl, alkoxy, amino, alkylamino,aminoalkyl, acyl, alkylthio, alkylsulfinyl, alkylsulfonyl, aryl,arylalkyl, alkylcarbonyloxy, or arylcarbonyloxy;

R⁸ is hydrogen, hydroxyl, halogen, thiol, alkyl, alkenyl, alkynyl, aryl,alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, or anarylalkyl;

R⁹ is hydrogen, nitro, alkyl, alkenyl, alkynyl, aryl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, arylalkyl, amino, aminoalkyl, amido,arylalkenyl, arylalkynyl, thionitroso or—(CH₂)₀₋₃(NR^(9c))₀₋₁C(═Z′)ZR^(9a);

Z is CR^(9d)R^(9e), S, NR^(9b) or O;

Z′ is O, S, or NR^(9f);

R^(9a), R^(9b), R^(9c), R^(9d), R^(9e) and R^(9f) are each independentlyhydrogen, acyl, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, arylalkyl, aryl, heterocyclic,heteroaromatic or a prodrug moiety;

R¹³ is hydrogen, hydroxy, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl; and

Y′ and Y are each independently hydrogen, halogen, hydroxyl, cyano,sulfhydryl, amino, amido, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl, andpharmaceutically acceptable salts thereof.

In one embodiment, X is CR^(6′)R⁶, R⁴ is NR^(4a)R^(4b), R^(4a) andR^(4b) are each alkyl (e.g., methyl), R², R^(2′), R³, R^(4′), R⁵,R^(5′), R⁶, R^(6′), R⁸, R⁹, R¹⁰, R¹¹ and R¹² are each hydrogen; J isOR^(7o); R^(7o) is alkyl (e.g., ethyl or t-butyl) and R^(7l) is alkyl(e.g., methyl) or aminoalkyl (e.g., dialkylaminoalkyl, such asdimethylaminoethyl).

In one embodiment, X is CR^(6′)R⁶, R⁴ is NR^(4a)R^(4b), R^(4a) andR^(4b) are each alkyl (e.g., methyl), R², R^(2′), R³, R^(4′), R⁵,R^(5′), R⁶, R^(6′), R⁸, R¹⁰, R¹¹ and R¹² are each hydrogen; R⁹ is amino;R^(7l) is alkyl (e.g., methyl); J is OR^(7o); R^(7o) is alkyl (e.g.,halogen substituted alkyl; such as fluorine substituted alkyl, forexample, CF₃CH₂—; ethyl or t-butyl).

In another embodiment, X is CR^(6′)R⁶, R⁴ is NR^(4a)R^(4b), R^(4a) andR^(4b) are each alkyl (e.g., methyl), R², R^(2′), R³, R^(4′), R⁵,R^(5′), R⁶, R^(6′), R⁸, R¹⁰, R¹¹ and R¹² are each hydrogen; R⁹ isaminoalkyl (e.g., t-butylaminoethyl); R^(7o) is alkyl (e.g., ethyl); andR^(7l) is alkyl (e.g., methyl).

In yet another embodiment, X is CR^(6′)R⁶, R⁴ is NR^(4a)R^(4b), R^(4a)and R^(4b) are each alkyl (e.g., methyl), R², R^(2′), R³, R^(4′), R⁵,R^(5′), R⁶R^(6′), R⁸, R⁹, R¹⁰, R¹¹ and R¹² are each hydrogen; J isNR^(7m)R^(7n); R^(7l) and R^(7m) are each hydrogen and R^(7n) is alkyl(e.g., t-butyl).

In a further embodiment, X is CR^(6′)R⁶, R⁴ is NR^(4a)R^(4b), R^(4a) andR^(4b) are each alkyl (e.g., methyl), R², R^(2′), R³, R^(4′), R⁵,R^(5′), R⁶, R^(6′), R^(7l), R⁸, R⁹, R¹⁰, R¹¹ and R¹² are each hydrogen;J is heteroaryl (e.g., pyrrolyl).

Examples of substituted tetracycline compounds of formula II include,for example:

and pharmaceutically acceptable salts thereof.

In another embodiment, the substituted tetracycline compound of theinvention is a compound of formula III:

wherein

X is CHC(R¹³Y′Y), CR^(6′)R⁶, C═CR^(6′)R⁶, S, NR⁶, or O;

R², R^(2′), R^(4′), R^(4a) and R^(4b) are each independently hydrogen,alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylsulfinyl,alkylsulfonyl, alkylamino, arylalkyl, aryl, heterocyclic, heteroaromaticor a prodrug moiety;

R³, R¹¹ and R¹² are each hydrogen or a prodrug moiety;

R⁴ is NR^(4a)R^(4b), alkyl, alkenyl, alkynyl, hydroxyl, halogen, orhydrogen;

R⁵ and R^(5′) are each independently hydroxyl, hydrogen, thiol,alkanoyl, aroyl, alkaroyl, aryl, heteroaromatic, alkyl, alkenyl,alkynyl, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino,arylalkyl, alkyl carbonyloxy, or aryl carbonyloxy;

R⁶ and R^(6′) are each independently hydrogen, methylene, absent,hydroxyl, halogen, thiol, alkyl, alkenyl, alkynyl, aryl, alkoxy,alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl;

R^(7p) is hydrogen, alkyl, alkenyl, alkynyl, hydroxyl, alkoxy,alkylthio, alkylsulfinyl, alkylsulfonyl, amino, aminoalkyl, alkylamino,aryl, acyl, arylalkyl, alkyl carbonyloxy, or arylcarbonyloxy;

R⁸ is hydrogen, hydroxyl, halogen, thiol, alkyl, alkenyl, alkynyl, aryl,alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, or anarylalkyl;

R⁹ is hydrogen, nitro, alkyl, alkenyl, alkynyl, aryl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, arylalkyl, amino, aminoalkyl, amido,arylalkenyl, arylalkynyl, thionitroso or—(CH₂)₀₋₃(NR^(9c))₀₋₁C(═Z′)ZR^(9a);

Z is CR^(9d)R^(9e), S, NR^(9b) or O;

Z′ is O, S, or NR^(9f);

R^(9a), R^(9b), R^(9c), R^(9d), R^(9e) and R^(9f) are each independentlyhydrogen, acyl, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, arylalkyl, aryl, heterocyclic,heteroaromatic or a prodrug moiety;

R^(10a) is hydrogen;

R¹³ is hydrogen, hydroxy, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl; and

Y′ and Y are each independently hydrogen, halogen, hydroxyl, cyano,sulfhydryl, amino, amido, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl, andpharmaceutically acceptable salts thereof.

In one embodiment, X is CR^(6′)R⁶, R⁴ may be NR^(4a)R^(4b), R^(4a) andR^(4b) may each be alkyl (e.g., methyl), R², R^(2′), R³, R^(4′), R⁵,R^(5′), R⁶, R^(6′), R⁸, R⁹, R^(10a), R¹¹ and R¹² may each be hydrogenand R^(7p) may be alkylamino (e.g., dialkylamino, such asdimethylamino), aminoalkyl (e.g., piperidinyl, such as4-methylpiperidinyl), acyl, or aryl (e.g., heteroaryl, such aspyrimidine or pyrazine).

Examples of substituted tetracycline compounds of formula III include,for example:

and pharmaceutically acceptable salts thereof.

In another embodiment, the substituted tetracycline compound of theinvention is a compound of formula IV:

wherein

X is CHC(R¹³Y′Y), CR^(6′)R⁶, C═CR^(6′)R⁶, S, NR⁶, or O;

R², R^(2′), R^(4′), R^(4a) and R^(4b) are each independently hydrogen,alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylsulfinyl,alkylsulfonyl, alkylamino, arylalkyl, aryl, heterocyclic, heteroaromaticor a prodrug moiety;

R³, R¹⁰, R¹¹ and R¹² are each hydrogen or a prodrug moiety;

R⁴ is NR^(4a)R^(4b), alkyl, alkenyl, alkynyl, hydroxyl, halogen, orhydrogen;

R⁵ and R^(5′) are each independently hydroxyl, hydrogen, thiol,alkanoyl, aroyl, alkaroyl, aryl, heteroaromatic, alkyl, alkenyl,alkynyl, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino,arylalkyl, alkyl carbonyloxy, or aryl carbonyloxy;

R⁶ and R^(6′) are each independently hydrogen, methylene, absent,hydroxyl, halogen, thiol, alkyl, alkenyl, alkynyl, aryl, alkoxy,alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl;

R^(7q) is heteroaryl;

R⁸ is hydrogen, hydroxyl, halogen, thiol, alkyl, alkenyl, alkynyl, aryl,alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, or anarylalkyl;

R⁹ is hydrogen, nitro, alkyl, alkenyl, alkynyl, aryl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, arylalkyl, amino, aminoalkyl, amido,arylalkenyl, arylalkynyl, thionitroso or—(CH₂)₀₋₃(NR^(9c))₀₋₁C(═Z′)ZR^(9a);

Z is CR^(9d)R^(9e), S, NR^(9b) or O;

Z′ is O, S, or NR^(9f);

R^(9a), R^(9b), R^(9c), R^(9d), R^(9e) and R^(9f) are each independentlyhydrogen, acyl, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, arylalkyl, aryl, heterocyclic,heteroaromatic or a prodrug moiety;

R¹³ is hydrogen, hydroxy, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl; and

Y′ and Y are each independently hydrogen, halogen, hydroxyl, cyano,sulfhydryl, amino, amido, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl, andpharmaceutically acceptable salts thereof.

In one embodiment, X is CR^(6′)R⁶, R⁴ may be NR^(4a)R^(4b), R^(4a) andR^(4b) may each be alkyl (e.g., methyl), R², R^(2′), R³, R^(4′), R⁵,R^(5′), R⁶, R^(6′), R⁸, R⁹, R¹⁰, R¹¹ and R¹² may each be hydrogen, andR^(7p) is heteroaryl (e.g., oxazolyl, isoxazolyl, thiazolyl orpyrrolyl).

Examples of substituted tetracycline compounds of formula IV include,for example:

and pharmaceutically acceptable salts thereof.

In another embodiment, the substituted tetracycline compound of theinvention is a compound of formula V:

wherein

X is CHC(R¹³Y′Y), CR^(6′)R⁶, C═CR^(6′)R⁶, S, NR⁶, or O;

R², R^(2′), R^(4′), R^(4a) and R^(4b) are each independently hydrogen,alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylsulfinyl,alkylsulfonyl, alkylamino, arylalkyl, aryl, heterocyclic, heteroaromaticor a prodrug moiety;

R³, R¹⁰, R¹¹ and R¹² are each hydrogen or a prodrug moiety;

R⁴ is NR^(4a)R^(4b), alkyl, alkenyl, alkynyl, hydroxyl, halogen, orhydrogen;

R⁵ and R^(5′) are each independently hydroxyl, hydrogen, thiol,alkanoyl, aroyl, alkaroyl, aryl, heteroaromatic, alkyl, alkenyl,alkynyl, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino,arylalkyl, alkyl carbonyloxy, or aryl carbonyloxy;

R⁶ and R^(6′) are each independently hydrogen, methylene, absent,hydroxyl, halogen, thiol, alkyl, alkenyl, alkynyl, aryl, alkoxy,alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl;

R^(7r) is hydrogen, alkyl, alkenyl, alkynyl, hydroxyl, alkoxy, amino,alkylamino, aminoalkyl, acyl, alkylthio, alkylsulfinyl, alkylsulfonyl,aryl, arylalkyl, alkylcarbonyloxy, or arylcarbonyloxy;

R⁸ is hydrogen, hydroxyl, halogen, thiol, alkyl, alkenyl, alkynyl, aryl,alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, or anarylalkyl;

R^(9x) is CN, CR^(9g)NR^(9h) or CR^(9i)R^(9j)NR^(9k)R^(9l);

R^(9g), R^(9h), R^(9i), R^(9j), R^(9k) and R^(9l) are each independentlyhydrogen, alkyl, alkenyl, alkynyl, hydroxyl, alkoxy, amino, alkylamino,aminoalkyl, acyl, alkylthio, alkylsulfinyl, alkylsulfonyl, aryl,arylalkyl, alkylcarbonyloxy, or arylcarbonyloxy;

R¹³ is hydrogen, hydroxy, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl; and

Y′ and Y are each independently hydrogen, halogen, hydroxyl, cyano,sulfhydryl, amino, amido, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl, andpharmaceutically acceptable salts thereof.

In one embodiment, X is CR^(6′)R⁶, R⁴ may be NR^(4a)R^(4b), R^(4a) andR^(4b) may each be alkyl (e.g., methyl), R², R^(2′), R³, R^(4′), R⁵,R^(5′)R⁶, R^(6′), R⁸, R¹⁰, R¹¹ and R¹² are each hydrogen, R^(7r) may bealkylamino (e.g., dialkylamino, such as dimethylamino) and R^(9x) is CN.Alternatively, R^(9x) may be CR^(9g)NR^(9h), R^(9g) is hydrogen andR^(9h) is alkoxy (e.g., methoxy). In another embodiment, R^(9x) may beCR^(9i)R^(9j)NR^(9k)R^(9l), R^(9i) and R^(9j) are each hydrogen, R^(9k)may be alkyl (e.g., methyl) and R^(9l) is alkoxy (e.g., methoxy). In yetanother embodiment, R^(9k) is hydrogen and R^(9l) is alkoxy (e.g.,methoxy).

In a further embodiment, X is CR^(6′)R⁶, R⁴ may be NR^(4a)R^(4b), R^(4a)and R^(4b) may each be alkyl (e.g., methyl), R², R^(2′), R³, R^(4′), R⁵,R^(5′), R⁶, R^(6′), R⁸, R¹⁰, R¹¹ and R¹² are each hydrogen, R^(7r) ishydrogen, R^(9f) is CR^(9i)R^(9j)NR^(9k)R^(9l); R^(9i), R^(9j) andR^(9k) are each hydrogen; and R^(9l) is alkoxy (e.g., ethoxy).

In yet another embodiment, In a further embodiment, X is CR^(6′)R⁶, R⁴may be NR^(4a)R^(4b), R^(4a) and R^(4b) may each be alkyl (e.g.,methyl), R², R^(2′), R³, R^(4′), R⁵, R^(5′), R⁶, R^(6′)R⁸, R⁹, R¹⁰, R¹¹and R¹² are each hydrogen, R^(7r) is hydrogen, R^(9x) isCR^(9i)R^(9j)NR^(9k)R^(9l); R^(9i) and R^(9j) are each hydrogen andR^(9k) is alkyl (e.g., methyl) and R^(9l) is alkoxyl (e.g., methoxy).

Examples of substituted tetracycline compounds of formula V include, forexample:

and pharmaceutically acceptable salts thereof.

In yet another embodiment, a substituted tetracycline compound of theinvention may be a compound of formula VI:

wherein

X is CHC(R¹³Y′Y), CR^(6′)R⁶, C═CR^(6′)R⁶, S, NR⁶, or O;

p is a single bond or a double bond;

Q is CR^(7s) when p is a double bond or Q is CR^(7s′)R^(7s″) when p is asingle bond;

R², R^(2′), R^(4′), R^(4a) and R^(4b) are each independently hydrogen,alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylsulfinyl,alkylsulfonyl, alkylamino, arylalkyl, aryl, heterocyclic, heteroaromaticor a prodrug moiety;

R³, R¹⁰, R¹¹ and R¹² are each hydrogen or a prodrug moiety;

R⁴ is NR^(4a)R^(4b), alkyl, alkenyl, alkynyl, hydroxyl, halogen, orhydrogen;

R⁵ and R^(5′) are each independently hydroxyl, hydrogen, thiol,alkanoyl, aroyl, alkaroyl, aryl, heteroaromatic, alkyl, alkenyl,alkynyl, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino,arylalkyl, alkyl carbonyloxy, or aryl carbonyloxy;

R⁶ and R^(6′) are each independently hydrogen, methylene, absent,hydroxyl, halogen, thiol, alkyl, alkenyl, alkynyl, aryl, alkoxy,alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl;

R^(7s), R^(7s′) and R^(7s″) are each hydrogen, alkyl, alkenyl, alkynyl,hydroxyl, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, amino,aminoalkyl, alkylamino, aryl, acyl, arylalkyl, alkyl carbonyloxy, orarylcarbonyloxy;

R⁸ is hydrogen, hydroxyl, halogen, thiol, alkyl, alkenyl, alkynyl, aryl,alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, or anarylalkyl;

R⁹ is hydrogen, nitro, alkyl, alkenyl, alkynyl, aryl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, arylalkyl, amino, aminoalkyl, amido,arylalkenyl, arylalkynyl, thionitroso or—(CH₂)₀₋₃(NR^(9c))₀₋₁C(═Z′)ZR^(9a);

Z is CR^(9d)R^(9e), S, NR^(9b) or O;

Z′ is O, S, or NR^(9f);

R^(9a), R^(9b), R^(9c), R^(9d), R^(9e) and R^(9f) are each independentlyhydrogen, acyl, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, arylalkyl, aryl, heterocyclic,heteroaromatic or a prodrug moiety;

R¹³ is hydrogen, hydroxy, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl; and

Y′ and Y are each independently hydrogen, halogen, hydroxyl, cyano,sulfhydryl, amino, amido, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, or an arylalkyl, andpharmaceutically acceptable salts thereof.

In one embodiment, X is CR^(6′)R⁶, R⁴ is NR^(4a)R^(4b), R^(4a) andR^(4b) are each alkyl (e.g., methyl) and R², R^(2′), R³, R^(4′), R⁵,R^(5′), R⁶, R^(6′), R⁸, R⁹, R¹⁰, R¹¹ and R¹² are each hydrogen. Inanother embodiment, p is a double bond and Q is CR^(7s). In a furtherembodiment, R^(7s) is amino, alkylamino (e.g., methylamino) ordialkylamino (e.g., dimethylamino).

Examples of substituted tetracycline compounds of formula VI include,for example:

and pharmaceutically acceptable salts thereof.

The tetracycline compounds of this invention can be synthesized usingthe methods described in the Schemes and/or by other techniques known tothose of ordinary skill in the art. The substituted tetracyclinecompounds of the invention can be synthesized using the methodsdescribed in the following schemes and by using art recognizedtechniques. All novel substituted tetracycline compounds describedherein are included in the invention as compounds.

In Scheme 1, a general synthetic scheme for synthesizing 7-substitutedtetracyclines is shown. A palladium catalyzed coupling of aniodosancycline (1) is performed to form a 7-substituted aldehydeintermediate (2). The aldehyde intermediate is reduced in the presenceof a hydroxylamine to give the desired product (3).

7- and 9-substituted tetracycline compounds may be synthesized byreacting the 7-iodo-9-aminoalkyl sancycline derivative (4) withtrimethylsilylethyne in the presence of a palladium catalyst to yield a7-substituted alkynyl intermediate. Subsequent acid hydrolysis yieldsthe 7-acyl intermediate (5). Further derivitization of the 9-positionmay be accomplished by reductive alkylation of the amino group witht-butyl aldehyde, hydrogen and palladium on carbon to form compound 6,which can then be reacted with a primary hydroxylamine to form the oxime7.

7- and 9-substituted tetracycline compounds may also be prepared asshown in Scheme 3. Beginning with a 7-iodo-9-nitro substitutedsancycline derivative (8), a Hiyama coupling followed by acid hydrolysisyields a 7-acyl-9-nitro intermediate (9). The nitro moiety may then bereduced to the amino group by hydrogen gas in the presence of apalladium catalyst (10). Reaction of the acyl group with a primaryhydroxylamine provides the product 11.

Scheme 4 also provides a method for synthesizing 7-substitutedtetracyclines. As described above, a palladium catalyzed carbonylationof an iodosancycline (1) is performed to form a 7-substituted aldehydeintermediate (2). The aldehyde intermediate is reduced in the presenceof a hydroxylamine to give compound 12, which may then be reacted withformaldehyde and triethylamine, followed by reduction to give thedesired product (3).

Scheme 5 details the synthesis of substituted tetracyclines with hydroxyin the 10-position. A 7-substituted tetracycline compound may be reactedwith N-(5-chloro-2-pyridyl)bis(trifluoromethanesulfonimide) to form atrifluoromethane substituted intermediate (14), which can then bereacted with ammonium formate in the presence of a palladium catalyst toform the desired product (15).

Scheme 6 outlines the general synthesis of 7-substituted tetracyclines.A 7-iodo sancycline derivative (1) may undergo a Stille coupling or aSuzuki coupling by reacting with an alkyl tin derivative or a boronicacid derivative in the presence of a palladium catalyst to form thedesired product (16).

The 7-substituted oxime derivatives may also be prepared as shown inScheme 7. An 7-iodo sancycline derivative (1) can be reacted with asubstituted alkyne in the presence of palladium to synthesize thealkynyl derivative 17. Compound 17 may be converted to the acylsubstituted compound 18 by any technique known in the art. The desiredoxime product 19 can be obtained by reacting the acyl moiety with aprimary hydroxylamine.

Scheme 8 is a general synthetic scheme showing the synthesis of7-substituted hydrazone compounds. A 7-substituted aldehyde tetracyclinederivative, prepared as described above in Scheme 4, is combined with aprimary hydrazone to form the desired product 20.

7-substituted hydrazines may also be synthesized as shown in Scheme 9.Starting with compound 2, synthesized as described in Scheme 4 above,may be reacted with a secondary hydrazine in the presence of a reducingagent to form compound 21.

Scheme 10 further depicts a method of synthesizing a 7-substitutedaminoalkyl tetracycline compound. Compound 2 is reacted with a primaryamine in the presence of a reducing agent to form the secondary amineintermediate (22), which is then mixed with an acid chloride to formcompound 23.

Scheme 11 describes a general method for preparing 9-substitutedaminoalkyl substituted tetracycline compounds. Compound 24 may bereacted directly with a secondary amine to form compounds similar to 26.Alternatively, compound 24 may be mixed with a primary amine to yieldthe substituted imine 25, which may be further reduced to produce theaminoalkyl compound 26.

7-substituted tetracycline may also be prepared as shown in Scheme 12.Starting again with compound 2, reductive alkylation with a dioxolanylsecondary amine yields the intermediate 27. Subsequently exposing 27 toacidic conditions removes the protecting group to form intermediate 28,which may then be reacted with a primary amine to form product 29.

Schemes 13 and 14 illustrate the general synthesis of cyclobutene7-substituted tetracycline compounds. Beginning with 30, tin reagent 31is synthesized by reacting 30 with a trimethylsilyl substituted alkyltinderivative.

Scheme 14 continues to show the synthesis of cyclobutenedione7-substituted tetracycline compounds, by reacting building block 31 with7-iodo substituted sancycline (1) in a Stille coupling reaction to form32. The amino substitution of product 33 is accomplished by reacting 32with a primary amine in methanol.

Scheme 15 illustrates the general synthesis of 9-substituted aminoalkylsubstituted tetracycline compounds. A 7-bromo-9-formyl substitutedtetracycline 34 may be reacted with a primary amine to yield the9-substituted imino derivative 35. This intermediate may be exposed to areducing agent (e.g., sodium cyanoborohydride) to yield the7-bromo-9-aminoalkyl substituted compound 36. Alternatively, compound 36may be prepared by reacting the starting material 34 with a reducingagent (e.g., sodium cyanoborohydride) in the presence of a secondaryamine. The 7-position may be dehalogenated in the presence of ammoniumformate, indium trichloride and a palladium catalyst to give the desiredproduct 37.

The term “alkyl” includes saturated aliphatic groups, includingstraight-chain alkyl groups (e.g., methyl, ethyl, propyl, butyl, pentyl,hexyl, heptyl, octyl, nonyl, decyl, etc.), branched-chain alkyl groups(isopropyl, tert-butyl, isobutyl, etc.), cycloalkyl (alicyclic) groups(cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl,cyclooctyl), alkyl substituted cycloalkyl groups, and cycloalkylsubstituted alkyl groups. The term alkyl further includes alkyl groups,which can further include oxygen, nitrogen, sulfur or phosphorous atomsreplacing one or more carbons of the hydrocarbon backbone. In certainembodiments, a straight chain or branched chain alkyl has 6 or fewercarbon atoms in its backbone (e.g., C₁-C₆ for straight chain, C₃-C₆ forbranched chain), and more preferably 4 or fewer. Likewise, preferredcycloalkyls have from 3-8 carbon atoms in their ring structure, and morepreferably have 5 or 6 carbons in the ring structure. The term C₁-C₆includes alkyl groups containing 1 to 6 carbon atoms.

Moreover, the term alkyl includes both “unsubstituted alkyls” and“substituted alkyls,” the latter of which refers to alkyl moietieshaving substituents replacing a hydrogen on one or more carbons of thehydrocarbon backbone. Such substituents can include, for example,alkenyl, alkynyl, halogen, hydroxyl, alkylcarbonyloxy, arylcarbonyloxy,alkoxycarbonyloxy, aryloxycarbonyloxy, carboxylate, alkylcarbonyl,arylcarbonyl, alkoxycarbonyl, aminocarbonyl, alkylaminocarbonyl,dialkylaminocarbonyl, alkylthiocarbonyl, alkoxyl, phosphate,phosphonato, phosphinato, cyano, amino (including alkyl amino,dialkylamino, arylamino, diarylamino, and alkylarylamino), acylamino(including alkylcarbonylamino, arylcarbonylamino, carbamoyl and ureido),amidino, imino, sulfhydryl, alkylthio, arylthio, thiocarboxylate,sulfates, alkylsulfinyl, sulfonato, sulfamoyl, sulfonamido, nitro,trifluoromethyl, cyano, azido, heterocyclyl, alkylaryl, or an aromaticor heteroaromatic moiety. Cycloalkyls can be further substituted, e.g.,with the substituents described above. An “alkylaryl” or an “arylalkyl”moiety is an alkyl substituted with an aryl (e.g., phenylmethyl(benzyl)). The term “alkyl” also includes the side chains of natural andunnatural amino acids.

The term “aryl” includes groups, including 5- and 6-membered single-ringaromatic groups that may include from zero to four heteroatoms, forexample, benzene, phenyl, pyrrole, furan, thiophene, thiazole,isothiaozole, imidazole, triazole, tetrazole, pyrazole, oxazole,isoxazole, pyridine, pyrazine, pyridazine, and pyrimidine, and the like.Furthermore, the term “aryl” includes multicyclic aryl groups, e.g.,tricyclic, bicyclic, e.g., naphthalene, benzoxazole, benzodioxazole,benzothiazole, benzoimidazole, benzothiophene, methylenedioxyphenyl,quinoline, isoquinoline, napthyridine, indole, benzofuran, purine,benzofuran, deazapurine, or indolizine. Those aryl groups havingheteroatoms in the ring structure may also be referred to as “arylheterocycles,” “heterocycles,” “heteroaryls” or “heteroaromatics.” Thearomatic ring can be substituted at one or more ring positions with suchsubstituents as described above, as for example, halogen, hydroxyl,alkoxy, alkylcarbonyloxy, arylcarbonyloxy, alkoxycarbonyloxy,aryloxycarbonyloxy, carboxylate, alkylcarbonyl, alkylaminoacarbonyl,arylalkyl aminocarbonyl, alkenylaminocarbonyl, alkylcarbonyl,arylcarbonyl, arylalkylcarbonyl, alkenylcarbonyl, alkoxycarbonyl,aminocarbonyl, alkylthiocarbonyl, phosphate, phosphonato, phosphinato,cyano, amino (including alkyl amino, dialkylamino, arylamino,diarylamino, and alkylarylamino), acylamino (includingalkylcarbonylamino, arylcarbonylamino, carbamoyl and ureido), amidino,imino, sulfhydryl, alkylthio, arylthio, thiocarboxylate, sulfates,alkylsulfinyl, sulfonato, sulfamoyl, sulfonamido, nitro,trifluoromethyl, cyano, azido, heterocyclyl, alkylaryl, or an aromaticor heteroaromatic moiety. Aryl groups can also be fused or bridged withalicyclic or heterocyclic rings which are not aromatic so as to form apolycycle (e.g., tetralin).

The term “alkenyl” includes unsaturated aliphatic groups analogous inlength and possible substitution to the alkyls described above, but thatcontain at least one double bond.

For example, the term “alkenyl” includes straight-chain alkenyl groups(e.g., ethylenyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl,octenyl, nonenyl, decenyl, etc.), branched-chain alkenyl groups,cycloalkenyl (alicyclic) groups (cyclopropenyl, cyclopentenyl,cyclohexenyl, cycloheptenyl, cyclooctenyl), alkyl or alkenyl substitutedcycloalkenyl groups, and cycloalkyl or cycloalkenyl substituted alkenylgroups. The term alkenyl further includes alkenyl groups which includeoxygen, nitrogen, sulfur or phosphorous atoms replacing one or morecarbons of the hydrocarbon backbone. In certain embodiments, a straightchain or branched chain alkenyl group has 6 or fewer carbon atoms in itsbackbone (e.g., C₂-C₆ for straight chain, C₃-C₆ for branched chain).Likewise, cycloalkenyl groups may have from 3-8 carbon atoms in theirring structure, and more preferably have 5 or 6 carbons in the ringstructure. The term C₂-C₆ includes alkenyl groups containing 2 to 6carbon atoms.

Moreover, the term alkenyl includes both “unsubstituted alkenyls” and“substituted alkenyls,” the latter of which refers to alkenyl moietieshaving substituents replacing a hydrogen on one or more carbons of thehydrocarbon backbone. Such substituents can include, for example, alkylgroups, alkynyl groups, halogens, hydroxyl, alkylcarbonyloxy,arylcarbonyloxy, alkoxycarbonyloxy, aryloxycarbonyloxy, carboxylate,alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aminocarbonyl,alkylaminocarbonyl, dialkylaminocarbonyl, alkylthiocarbonyl, alkoxyl,phosphate, phosphonato, phosphinato, cyano, amino (including alkylamino, dialkylamino, arylamino, diarylamino, and alkylarylamino),acylamino (including alkylcarbonylamino, arylcarbonylamino, carbamoyland ureido), amidino, imino, sulfhydryl, alkylthio, arylthio,thiocarboxylate, sulfates, alkylsulfinyl, sulfonato, sulfamoyl,sulfonamido, nitro, trifluoromethyl, cyano, azido, heterocyclyl,alkylaryl, or an aromatic or heteroaromatic moiety.

The term “alkynyl” includes unsaturated aliphatic groups analogous inlength and possible substitution to the alkyls described above, butwhich contain at least one triple bond.

For example, the term “alkynyl” includes straight-chain alkynyl groups(e.g., ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl, octynyl,nonynyl, decynyl, etc.), branched-chain alkynyl groups, and cycloalkylor cycloalkenyl substituted alkynyl groups. The term alkynyl furtherincludes alkynyl groups which include oxygen, nitrogen, sulfur orphosphorous atoms replacing one or more carbons of the hydrocarbonbackbone. In certain embodiments, a straight chain or branched chainalkynyl group has 6 or fewer carbon atoms in its backbone (e.g., C₂-C₆for straight chain, C₃-C₆ for branched chain). The term C₂-C₆ includesalkynyl groups containing 2 to 6 carbon atoms.

Moreover, the term alkynyl includes both “unsubstituted alkynyls” and“substituted alkynyls,” the latter of which refers to alkynyl moietieshaving substituents replacing a hydrogen on one or more carbons of thehydrocarbon backbone. Such substituents can include, for example, alkylgroups, alkynyl groups, halogens, hydroxyl, alkylcarbonyloxy,arylcarbonyloxy, alkoxycarbonyloxy, aryloxycarbonyloxy, carboxylate,alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aminocarbonyl,alkylaminocarbonyl, dialkylaminocarbonyl, alkylthiocarbonyl, alkoxyl,phosphate, phosphonato, phosphinato, cyano, amino (including alkylamino, dialkylamino, arylamino, diarylamino, and alkylarylamino),acylamino (including alkylcarbonylamino, arylcarbonylamino, carbamoyland ureido), amidino, imino, sulfhydryl, alkylthio, arylthio,thiocarboxylate, sulfates, alkylsulfinyl, sulfonato, sulfamoyl,sulfonamido, nitro, trifluoromethyl, cyano, azido, heterocyclyl,alkylaryl, or an aromatic or heteroaromatic moiety.

Unless the number of carbons is otherwise specified, “lower alkyl”includes an alkyl group, as defined above, but having from one to fivecarbon atoms in its backbone structure. “Lower alkenyl” and “loweralkynyl” have chain lengths of, for example, 2-5 carbon atoms.

The term “acyl” includes compounds and moieties which contain the acylradical (CH₃CO—) or a carbonyl group. It includes substituted acylmoieties. The term “substituted acyl” includes acyl groups where one ormore of the hydrogen atoms are replaced by for example, alkyl groups,alkynyl groups, halogens, hydroxyl, alkylcarbonyloxy, arylcarbonyloxy,alkoxycarbonyloxy, aryloxycarbonyloxy, carboxylate, alkylcarbonyl,arylcarbonyl, alkoxycarbonyl, aminocarbonyl, alkylaminocarbonyl,dialkylaminocarbonyl, alkylthiocarbonyl, alkoxyl, phosphate,phosphonato, phosphinato, cyano, amino (including alkyl amino,dialkylamino, arylamino, diarylamino, and alkylarylamino), acylamino(including alkylcarbonylamino, arylcarbonylamino, carbamoyl and ureido),amidino, imino, sulfhydryl, alkylthio, arylthio, thiocarboxylate,sulfates, alkylsulfinyl, sulfonato, sulfamoyl, sulfonamido, nitro,trifluoromethyl, cyano, azido, heterocyclyl, alkylaryl, or an aromaticor heteroaromatic moiety.

The term “acylamino” includes moieties wherein an acyl moiety is bondedto an amino group. For example, the term includes alkylcarbonylamino,arylcarbonylamino, carbamoyl and ureido groups.

The term “aroyl” includes compounds and moieties with an aryl orheteroaromatic moiety bound to a carbonyl group. Examples of aroylgroups include phenylcarboxy, naphthyl carboxy, etc.

The terms “alkoxyalkyl,” “alkylaminoalkyl” and “thioalkoxyalkyl” includealkyl groups, as described above, which further include oxygen, nitrogenor sulfur atoms replacing one or more carbons of the hydrocarbonbackbone, e.g., oxygen, nitrogen or sulfur atoms.

The term “alkoxy” includes substituted and unsubstituted alkyl, alkenyl,and alkynyl groups covalently linked to an oxygen atom. Examples ofalkoxy groups include methoxy, ethoxy, isopropyloxy, propoxy, butoxy,and pentoxy groups. Examples of substituted alkoxy groups includehalogenated alkoxy groups. The alkoxy groups can be substituted withgroups such as alkenyl, alkynyl, halogen, hydroxyl, alkylcarbonyloxy,arylcarbonyloxy, alkoxycarbonyloxy, aryloxycarbonyloxy, carboxylate,alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aminocarbonyl,alkylaminocarbonyl, dialkylaminocarbonyl, alkylthiocarbonyl, alkoxyl,phosphate, phosphonato, phosphinato, cyano, amino (including alkylamino, dialkylamino, arylamino, diarylamino, and alkylarylamino),acylamino (including alkylcarbonylamino, arylcarbonylamino, carbamoyland ureido), amidino, imino, sulfhydryl, alkylthio, arylthio,thiocarboxylate, sulfates, alkylsulfinyl, sulfonato, sulfamoyl,sulfonamido, nitro, trifluoromethyl, cyano, azido, heterocyclyl,alkylaryl, or an aromatic or heteroaromatic moieties. Examples ofhalogen substituted alkoxy groups include, but are not limited to,fluoromethoxy, difluoromethoxy, trifluoromethoxy, chloromethoxy,dichloromethoxy, trichloromethoxy, etc.

The term “amine” or “amino” includes compounds where a nitrogen atom iscovalently bonded to at least one carbon or heteroatom. The termincludes “alkyl amino” which comprises groups and compounds wherein thenitrogen is bound to at least one additional alkyl group. The term“dialkyl amino” includes groups wherein the nitrogen atom is bound to atleast two additional alkyl groups. The term “arylamino” and“diarylamino” include groups wherein the nitrogen is bound to at leastone or two aryl groups, respectively. The term “alkylarylamino,”“alkylaminoaryl” or “arylaminoalkyl” refers to an amino group which isbound to at least one alkyl group and at least one aryl group. The term“alkaminoalkyl” refers to an alkyl, alkenyl, or alkynyl group bound to anitrogen atom which is also bound to an alkyl group.

The term “amide,” “amido” or “aminocarbonyl” includes compounds ormoieties which contain a nitrogen atom which is bound to the carbon of acarbonyl or a thiocarbonyl group. The term includes “alkaminocarbonyl”or “alkylaminocarbonyl” groups which include alkyl, alkenyl, aryl oralkynyl groups bound to an amino group bound to a carbonyl group. Itincludes arylaminocarbonyl and arylcarbonylamino groups which includearyl or heteroaryl moieties bound to an amino group which is bound tothe carbon of a carbonyl or thiocarbonyl group. The terms“alkylaminocarbonyl,” “alkenylaminocarbonyl,” “alkynylaminocarbonyl,”“arylaminocarbonyl,” “alkylcarbonylamino,” “alkenylcarbonylamino,”“alkynylcarbonylamino,” and “arylcarbonylamino” are included in term“amide.” Amides also include urea groups (aminocarbonylamino) andcarbamates (oxycarbonylamino).

The term “carbonyl” or “carboxy” includes compounds and moieties whichcontain a carbon connected with a double bond to an oxygen atom. Thecarbonyl can be further substituted with any moiety which allows thecompounds of the invention to perform its intended function. Forexample, carbonyl moieties may be substituted with alkyls, alkenyls,alkynyls, aryls, alkoxy, aminos, etc. Examples of moieties which containa carbonyl include aldehydes, ketones, carboxylic acids, amides, esters,anhydrides, etc.

The term “thiocarbonyl” or “thiocarboxy” includes compounds and moietieswhich contain a carbon connected with a double bond to a sulfur atom.

The term “ether” includes compounds or moieties which contain an oxygenbonded to two different carbon atoms or heteroatoms. For example, theterm includes “alkoxyalkyl” which refers to an alkyl, alkenyl, oralkynyl group covalently bonded to an oxygen atom which is covalentlybonded to another alkyl group.

The term “ester” includes compounds and moieties which contain a carbonor a heteroatom bound to an oxygen atom which is bonded to the carbon ofa carbonyl group. The term “ester” includes alkoxycarboxy groups such asmethoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl,pentoxycarbonyl, etc. The alkyl, alkenyl, or alkynyl groups are asdefined above.

The term “thioether” includes compounds and moieties which contain asulfur atom bonded to two different carbon or hetero atoms. Examples ofthioethers include, but are not limited to alkthioalkyls,alkthioalkenyls, and alkthioalkynyls. The term “alkthioalkyls” includecompounds with an alkyl, alkenyl, or alkynyl group bonded to a sulfuratom which is bonded to an alkyl group. Similarly, the term“alkthioalkenyls” and alkthioalkynyls” refer to compounds or moietieswherein an alkyl, alkenyl, or alkynyl group is bonded to a sulfur atomwhich is covalently bonded to an alkynyl group.

The term “hydroxy” or “hydroxyl” includes groups with an —OH or —O⁻.

The term “halogen” includes fluorine, bromine, chlorine, iodine, etc.The term “perhalogenated” generally refers to a moiety wherein allhydrogens are replaced by halogen atoms.

The terms “polycyclyl” or “polycyclic radical” refer to two or morecyclic rings (e.g., cycloalkyls, cycloalkenyls, cycloalkynyls, arylsand/or heterocyclyls) in which two or more carbons are common to twoadjoining rings, e.g., the rings are “fused rings.” Rings that arejoined through non-adjacent atoms are termed “bridged” rings. Each ofthe rings of the polycycle can be substituted with such substituents asdescribed above, as for example, halogen, hydroxyl, alkylcarbonyloxy,arylcarbonyloxy, alkoxycarbonyloxy, aryloxycarbonyloxy, carboxylate,alkylcarbonyl, alkoxycarbonyl, alkylaminoacarbonyl,arylalkylaminocarbonyl, alkenylaminocarbonyl, alkylcarbonyl,arylcarbonyl, arylalkyl carbonyl, alkenylcarbonyl, aminocarbonyl,alkylthiocarbonyl, alkoxyl, phosphate, phosphonato, phosphinato, cyano,amido, amino (including alkyl amino, dialkylamino, arylamino,diarylamino, and alkylarylamino), acylamino (includingalkylcarbonylamino, arylcarbonylamino, carbamoyl and ureido), amidino,imino, sulfhydryl, alkylthio, arylthio, thiocarboxylate, sulfates,alkylsulfinyl, sulfonato, sulfamoyl, sulfonamido, nitro,trifluoromethyl, cyano, azido, heterocyclyl, alkyl, alkylaryl, or anaromatic or heteroaromatic moiety.

The term “heteroatom” includes atoms of any element other than carbon orhydrogen. Preferred heteroatoms are nitrogen, oxygen, sulfur andphosphorus.

The term “prodrug moiety” includes moieties which can be metabolized invivo to a hydroxyl group and moieties which may advantageously remainesterified in vivo. Preferably, the prodrugs moieties are metabolized invivo by esterases or by other mechanisms to hydroxyl groups or otheradvantageous groups. Examples of prodrugs and their uses are well knownin the art (See, e.g., Berge et al. (1977) “Pharmaceutical Salts,” J.Pharm. Sci. 66:1-19). The prodrugs can be prepared in situ during thefinal isolation and purification of the compounds, or by separatelyreacting the purified compound in its free acid form or hydroxyl with asuitable esterifying agent. Hydroxyl groups can be converted into estersvia treatment with a carboxylic acid. Examples of prodrug moietiesinclude substituted and unsubstituted, branch or unbranched lower alkylester moieties, (e.g., propionic acid esters), lower alkenyl esters,di-lower alkyl-amino lower-alkyl esters (e.g., dimethylaminoethylester), acylamino lower alkyl esters (+, acetyloxymethyl ester), acyloxylower alkyl esters (e.g., pivaloyloxymethyl ester), aryl esters (phenylester), aryl-lower alkyl esters (e.g., benzyl ester), substituted (e.g.,with methyl, halo, or methoxy substituents) aryl and aryl-lower alkylesters, amides, lower-alkyl amides, di-lower alkyl amides, and hydroxyamides. Preferred prodrug moieties are propionic acid esters and acylesters.

It will be noted that the structure of some of the tetracyclinecompounds of this invention includes asymmetric carbon atoms. It is tobe understood accordingly that the isomers arising from such asymmetry(e.g., all enantiomers and diastereomers) are included within the scopeof this invention, unless indicated otherwise. Such isomers can beobtained in substantially pure form by classical separation techniquesand by stereochemically controlled synthesis. Furthermore, thestructures and other compounds and moieties discussed in thisapplication also include all tautomers thereof.

In another further embodiment, the substituted tetracycline compound isadministered in combination with a second agent.

The language “in combination with” a second agent includesco-administration of the tetracycline compound with the second agent,administration of the tetracycline compound first, followed by thesecond agent and administration of the second agent, followed by thetetracycline compound. The second agent may be any agent which is knownin the art to treat, prevent, or reduce the symptoms of a skin disorder.Furthermore, the second agent may be any agent of benefit to the subjectwhen administered in combination with the administration of antetracycline compound.

In another embodiment, the invention pertains to pharmaceuticalcompositions comprising an effective amount of a substitutedtetracycline compound of the invention for the treatment of aninflammatory skin disorder and a pharmaceutically acceptable carrier.

The language “pharmaceutically acceptable carrier” includes substancescapable of being coadministered with the tetracycline compound(s), andwhich allow both to perform their intended function, e.g., treat orprevent an inflammatory skin disorder. Suitable pharmaceuticallyacceptable carriers include but are not limited to water, saltsolutions, alcohol, vegetable oils, polyethylene glycols, gelatin,lactose, amylose, magnesium stearate, talc, silicic acid, viscousparaffin, perfume oil, fatty acid monoglycerides and diglycerides,petroethral fatty acid esters, hydroxymethyl-cellulose,polyvinylpyrrolidone, etc. The pharmaceutical preparations can besterilized and if desired mixed with auxiliary agents, e.g., lubricants,preservatives, stabilizers, wetting agents, emulsifiers, salts forinfluencing osmotic pressure, buffers, colorings, flavorings and/oraromatic substances and the like which do not deleteriously react withthe active compounds of the invention.

The tetracycline compounds of the invention that are basic in nature arecapable of forming a wide variety of salts with various inorganic andorganic acids. The acids that may be used to prepare pharmaceuticallyacceptable acid addition salts of the tetracycline compounds of theinvention that are basic in nature are those that form non-toxic acidaddition salts, i.e., salts containing pharmaceutically acceptableanions, such as the hydrochloride, hydrobromide, hydroiodide, nitrate,sulfate, bisulfate, phosphate, acid phosphate, isonicotinate, acetate,lactate, salicylate, citrate, acid citrate, tartrate, pantothenate,bitartrate, ascorbate, succinate, maleate, gentisinate, fumarate,gluconate, glucaronate, saccharate, formate, benzoate, glutamate,methanesulfonate, ethanesulfonate, benzenesulfonate, p-toluenesulfonateand palmoate [i.e., 1,1′-methylene-bis-(2-hydroxy-3-naphthoate)] salts.Although such salts must be pharmaceutically acceptable foradministration to a subject, e.g., a mammal, it is often desirable inpractice to initially isolate a tetracycline compound of the inventionfrom the reaction mixture as a pharmaceutically unacceptable salt andthen simply convert the latter back to the free base compound bytreatment with an alkaline reagent and subsequently convert the latterfree base to a pharmaceutically acceptable acid addition salt. The acidaddition salts of the base compounds of this invention are readilyprepared by treating the base compound with a substantially equivalentamount of the chosen mineral or organic acid in an aqueous solventmedium or in a suitable organic solvent, such as methanol or ethanol.Upon careful evaporation of the solvent, the desired solid salt isreadily obtained. The preparation of other tetracycline compounds of theinvention not specifically described in the foregoing experimentalsection can be accomplished using combinations of the reactionsdescribed above that will be apparent to those skilled in the art.

The tetracycline compounds of the invention that are acidic in natureare capable of forming a wide variety of base salts. The chemical basesthat may be used as reagents to prepare pharmaceutically acceptable basesalts of those tetracycline compounds of the invention that are acidicin nature are those that form non-toxic base salts with such compounds.Such non-toxic base salts include, but are not limited to those derivedfrom such pharmaceutically acceptable cations such as alkali metalcations (e.g., potassium and sodium) and alkaline earth metal cations(e.g., calcium and magnesium), ammonium or water-soluble amine additionsalts such as N-methylglucamine-(meglumine), and the loweralkanolammonium and other base salts of pharmaceutically acceptableorganic amines. The pharmaceutically acceptable base addition salts oftetracycline compounds of the invention that are acidic in nature may beformed with pharmaceutically acceptable cations by conventional methods.Thus, these salts may be readily prepared by treating the tetracyclinecompound of the invention with an aqueous solution of the desiredpharmaceutically acceptable cation and evaporating the resultingsolution to dryness, preferably under reduced pressure. Alternatively, alower alkyl alcohol solution of the tetracycline compound of theinvention may be mixed with an alkoxide of the desired metal and thesolution subsequently evaporated to dryness.

The tetracycline compounds of the invention and pharmaceuticallyacceptable salts thereof can be administered via either the oral,parenteral or topical routes. In general, these compounds are mostdesirably administered in effective dosages, depending upon the weightand condition of the subject being treated and the particular route ofadministration chosen. Variations may occur depending upon the speciesof the subject being treated and its individual response to saidmedicament, as well as on the type of pharmaceutical formulation chosenand the time period and interval at which such administration is carriedout.

The tetracycline compounds of the invention may be administered alone orin combination with pharmaceutically acceptable carriers or diluents byany of the routes previously mentioned, and the administration may becarried out in single or multiple doses. For example, the noveltherapeutic agents of this invention can be administered advantageouslyin a wide variety of different dosage forms, i.e., they may be combinedwith various pharmaceutically acceptable inert carriers in the form oftablets, capsules, lozenges, troches, hard candies, powders, sprays(e.g., aerosols, etc.), creams, salves, suppositories, jellies, gels,pastes, lotions, ointments, aqueous suspensions, injectable solutions,elixirs, syrups, and the like. Such carriers include solid diluents orfillers, sterile aqueous media and various non-toxic organic solvents,etc. Moreover, oral pharmaceutical compositions can be suitablysweetened and/or flavored. In general, the therapeutically-effectivecompounds of this invention are present in such dosage forms atconcentration levels ranging from about 5.0% to about 70% by weight.

For oral administration, tablets containing various excipients such asmicrocrystalline cellulose, sodium citrate, calcium carbonate, dicalciumphosphate and glycine may be employed along with various disintegrantssuch as starch (and preferably corn, potato or tapioca starch), alginicacid and certain complex silicates, together with granulation binderslike polyvinylpyrrolidone, sucrose, gelatin and acacia. Additionally,lubricating agents such as magnesium stearate, sodium lauryl sulfate andtalc are often very useful for tabletting purposes. Solid compositionsof a similar type may also be employed as fillers in gelatin capsules;preferred materials in this connection also include lactose or milksugar as well as high molecular weight polyethylene glycols. Whenaqueous suspensions and/or elixirs are desired for oral administration,the active ingredient may be combined with various sweetening orflavoring agents, coloring matter or dyes, and, if so desired,emulsifying and/or suspending agents as well, together with suchdiluents as water, ethanol, propylene glycol, glycerin and various likecombinations thereof. The compositions of the invention may beformulated such that the tetracycline compositions are released over aperiod of time after administration.

For parenteral administration (including intraperitoneal, subcutaneous,intravenous, intradermal or intramuscular injection), solutions of atherapeutic compound of the present invention in either sesame or peanutoil or in aqueous propylene glycol may be employed. The aqueoussolutions should be suitably buffered (preferably pH greater than 8) ifnecessary and the liquid diluent first rendered isotonic. These aqueoussolutions are suitable for intravenous injection purposes. The oilysolutions are suitable for intraarticular, intramuscular andsubcutaneous injection purposes. The preparation of all these solutionsunder sterile conditions is readily accomplished by standardpharmaceutical techniques well known to those skilled in the art. Forparenteral application, examples of suitable preparations includesolutions, preferably oily or aqueous solutions as well as suspensions,emulsions, or implants, including suppositories. Therapeutic compoundsmay be formulated in sterile form in multiple or single dose formatssuch as being dispersed in a fluid carrier such as sterile physiologicalsaline or 5% saline dextrose solutions commonly used with injectables.

Additionally, tetracycline compounds of the present invention may beadministered topically when treating inflammatory conditions of theskin. Examples of methods of topical administration include transdermal,buccal or sublingual application. For topical applications, therapeuticcompounds can be suitably admixed in a pharmacologically inert topicalcarrier such as a gel, an ointment, a lotion or a cream. Such topicalcarriers include water, glycerol, alcohol, propylene glycol, fattyalcohols, triglycerides, fatty acid esters, or mineral oils. Otherpossible topical carriers are liquid petrolatum, isopropylpalmitate,polyethylene glycol, ethanol 95%, polyoxyethylene monolaurate 5% inwater, sodium lauryl sulfate 5% in water, and the like. In addition,materials such as anti-oxidants, humectants, viscosity stabilizers andthe like also may be added if desired.

In addition to treatment of human subjects, the therapeutic methods ofthe invention also will have significant veterinary applications, e.g.for treatment of livestock such as cattle, sheep, goats, cows, swine andthe like; poultry such as chickens, ducks, geese, turkeys and the like;horses; and pets such as dogs and cats.

It will be appreciated that the actual preferred amounts of activecompounds used in a given therapy will vary according to the specificcompound being used, the particular compositions formulated, the mode ofapplication, the particular site of administration, etc. Optimaladministration rates for a given protocol of administration can bereadily ascertained by those skilled in the art using conventionaldosage determination tests conducted with regard to the foregoingguidelines.

In general, compounds of the invention for treatment can be administeredto a subject in dosages used in prior tetracycline therapies. See, forexample, the Physicians'Desk Reference. For example, a suitableeffective dose of one or more compounds of the invention will be in therange of from 0.01 to 100 milligrams per kilogram of body weight ofrecipient per day, preferably in the range of from 0.1 to 50 milligramsper kilogram body weight of recipient per day, more preferably in therange of 1 to 20 milligrams per kilogram body weight of recipient perday. The desired dose is suitably administered once daily, or severalsub-doses, e.g., 2 to 5 sub-doses, are administered at appropriateintervals through the day, or other appropriate schedule.

It will also be understood that normal, conventionally known precautionswill be taken regarding the administration of tetracyclines generally toensure their efficacy under normal use circumstances. Especially whenemployed for therapeutic treatment of humans and animals in vivo, thepractitioner should take all sensible precautions to avoidconventionally known contradictions and toxic effects. Thus, theconventionally recognized adverse reactions of gastrointestinal distressand inflammations, the renal toxicity, hypersensitivity reactions,changes in blood, and impairment of absorption through aluminum,calcium, and magnesium ions should be duly considered in theconventional manner.

Furthermore, the invention also pertains to the use of a substitutedtetracycline of the invention, for the preparation of a medicament. Themedicament may include a pharmaceutically acceptable carrier and thetetracycline compound is an effective amount, e.g., an effective amountto treat an inflammatory skin disorder.

In one embodiment, the compounds of the invention are compounds of Table2.

TABLE 2 Compound Code Compound A

B

C

D

E

F

G

H

I

J

K

L

M

N

O

P

Q

R

S

T

U

V

W

X

Y

Z

AA

AB

AC

AD

AE

AF

AG

AH

AI

AJ

AK

AL

AM

AN

AO

AP

AQ

AR

AS

AT

AU

AV

AW

AX

AY

AZ

BA

BB

BC

BD

BE

BF

EXEMPLIFICATION OF THE INVENTION Example 1 Synthesis of SelectedCompounds of the Invention(4S,4aS,5aR,12aS)-4-Dimethylamino-3,10,12,12a-tetrahydroxy-7-[(methoxy-methyl-amino)-methyl]-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydro-naphthacene-2-carboxylicacid amide (Compound P)

A solution of 7-formylsancycline TFA salt (2.23 g) andN,O-dimethylhydroxylamine hydrochloride (780 mg) inN,N-dimethylacetamide (15 mL) was stirred for 10 minutes at roomtemperature under argon atmosphere. To this solution was added sodiumcyanoborohydride (302 mg). The solution was stirred for 5 minutes andmonitored by LC-MS. The reaction mixture was poured into diethyl ether,and the resulting precipitates were collected by filtration undervacuum. The crude product was purified by prep-HPLC using a C18 column(linear gradient 10-40% acetonitrile in 20 mM aqueous triethanolamine,pH 7.4). The prep-HPLC fractions were collected, and the organic solvent(acetonitrile) was evaporated in vacuo. The resulting aqueous solutionwas loaded onto a clean PDVB SPE column, washed with distilled water,then with a 0.1 M sodium acetate solution followed by distilled water.The product was eluted with 0.1% TFA in acetonitrile. Afterconcentrating under vacuum, 565 mg was obtained as a TFA salt. The TFAsalt was converted to the hydrochloride salt by adding methanolic HClfollowed by in vacuo evaporation. This process was repeated twice togive a yellow solid: MS (Mz+1=488). ¹H NMR (300 MHz, CD₃OD) δ 7.46 (d,1H, J=8.6 Hz), 6.81 (d, 1H, J=8.6 Hz), 4.09 (d, 1H, J=1.0 Hz), 3.79 (d,1H, J=13.1 Hz), 3.73 (d, 1H, J=13.1 Hz), 3.36 (m, 1H), 3.27 (s, 3H),3.08-2.95 (8H), 2.61 (s, 3H), 2.38 (t, 1H, J=14.8), 2.22 (m, 1H), 1.64(m, 1H). Compounds Y, U and AV were also prepared in a similar mannerand compound BF may also be prepared in a similar manner.

(4S,4aS,5aR,12aS)-4-Dimethylamino-9-[(2,2-dimethyl-propylamino)-methyl]-7-(1-ethoxyimino-ethyl)-3,10,12,12a-tetrahydroxy-1,1′-dioxo-1,4,4a,5,5a,6,11,12a-octahydro-naphthacene-2-carboxylicacid amide (Compound N)

A mixture of 7-iodo-9-aminomethylsancycline (3.26 mmol), Pd(PPh₃)₄(0.326 mmol), Pd(OAc)₂ (0.326 mmol), CuI (0.326 mmol) in acetonitrile(50 mL) and N,N-dimethylacetamide (8 mL) was purged with argon. Whileunder argon atmosphere, triethylamine (16.25 mmol) andtrimethylacetylene (4.9 mmol) were added and the reaction mixture wasstirred for 4 hours at 50-60° C. The solvent was partially evaporatedand the crude intermediate was cooled with an ice-bath and sulfuric acidsolution (conc H₂SO₄:H₂O, 4/1, 25 mL) was added slowly and stirred for 5minutes. The reaction mixture was then slowly poured into 1.2 L of waterand filtered through celite pad. The filtrate was purified using shortDVB column to give the intermediate 7-acetyl-9-aminomethylsancycline.

To a solution of 7-acetyl-9-aminomethylsancycline (1 mmol) in methanol(20 mL) was added triethylamine (0.7 mL). To the resulting suspensionwas added trimethylacetaldehyde (7.37 mmol) and the mixture was stirredfor 20 minutes. Palladium on carbon (5%, 53% water, 300 mg) was addedand the reaction mixture was stirred overnight under H₂ atmosphere at 20psi. Excess trimethylacetaldehyde (3.7 mmol), Pd—C (150 mg) andtriethylamine (0.2 mL) were then added and stirred for an additional 6hours. The reaction mixture was then filtered through celite and thesolvent was evaporated reduced. The crude product was purified byprep-HPLC using C18 column (linear gradient 5-32% acetonitrile in waterwith 0.1% TFA) to give7-acetyl-9-(2,2-dimethylpropyl-amino)-methyl-sancycline.

A solution of 7-acetyl-9-[(2,2-dimethylpropylamino)-methyl]-sancycline(0.383 mmol) and O-ethylhyroxylamine hydrochloride (2.30 mmol) inmethanol (15 mL) was stirred overnight. The solvent was evaporated andpurified by prep-HPLC using C18 column (linear gradient 15-30%acetonitrile in water with 0.1% TFA) to give a yellow solid: MS(Mz+1=599); ¹H NMR (300 MHz, CD₃OD)

7.60 (s, 1H), 4.33 (s, 2H), 5.06 (m, 2H), 4.16 (2H, q, J=7.0 Hz), 4.08(s, 1H), 3.11-2.90 (1H), 2.52 (m, 1H), 2.18 (m, 1H), 2.15 (s, 3H), 1.28(3H, t, J=7.0 Hz), 1.06 (s, 9H).

(4S,4aS,5aR,12aS)-9-Amino-7-(1-tert-butoxyimino-ethyl)-4-dimethylamino-3,10,12,12a-tetrahydroxy-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydro-naphthacene-2-carboxylicacid amide (Compound Q)

A mixture of 7-iodo-9-nitrosancycline (10 mmol), Pd(PPh₃)₄ (0.5 mmol),Pd(OAc)₂ (0.5 mmol), CuI (0.5 mmol) in acetonitrile (80 mL) was cooledwith an ice-bath and purged with argon. While under argon atmosphere andat an ice bath temperature, triethylamine (50 mmol) andtrimethylacetylene (15 mmol) were added. The ice-bath was removed andthe reaction mixture was stirred for 1.75 hours. The acetonitrile waspartially removed. To the crude intermediate at an ice-bath temperaturea sulfuric acid solution (conc H₂SO₄:H₂O, 4/1, 50 mL) was slowly addedand the solution was stirred for 10 minutes. The crude product wasslowly poured on to 3 L of deionized water and filtered through celitepad. The filtrate was taken and the compound was purified using shortDVB column to give 7-acetyl-9-nitrosancycline.

To a mixture of 7-acetyl-9-nitrosancycline (0.94 mmol) and Pd—C (5%, 53%water, 290 mg) in methanol (30 mL) was added a few drops of acetic acid.The reaction mixture was purged with H₂ and stirred under H₂ atmosphereat 20 psi for 1 hour. The reaction mixture was then filtered throughcelite, the filtrate was taken, solvent was evaporated and purified byprep-HPLC using C18 column (linear gradient 5-30% acetonitrile in waterwith 0.1% TFA) to give 7-acetyl-9-aminosancycline.

A solution of 7-acetyl-9-aminosancycline hydrochloride (0.79 mmol) andO-tert-butylhydroxylamine hydrochloride (4.74 mmol) in methanol (10 mL)was stirred overnight. The methanol was evaporated and the resultingcompound purified by prep-HPLC using C18 column (linear gradient 15-35%acetonitrile in water with 0.1% TFA) to give a yellow solid: MS(Mz+1=543); ¹H NMR (300 MHz, CD₃OD)

7.54 (s, 1H), 4.14 (s, 1H), 3.14-2.99 (9H), 2.52 (m, 1H), 2.20 (m, 1H),2.16 (s, 3H), 1.32 (s, 9H). Compounds M and R were also prepared in asimilar manner and compound BE may also be prepared in a similar manner.

(4S,4aS,5aR,12aS)-9-Amino-4-dimethylamino-3,10,12,12a-tetrahydroxy-1,1,1-dioxo-7-[1-(2,2,2-trifluoro-ethoxyimino)-ethyl]-1,4,4a,5,5a,6,11,12a-octahydro-naphthacene-2-carboxylicacid amide (Compound A W)

A solution of 7-acetyl-9-amino-sancycline (1.5 mmol) and2,2,2-trifluoroethylhydroxylamine hydrochloride (3 mmol) in methanol (20mL) was stirred overnight. The methanol was evaporated and the crudeproduct was purified by prep-HPLC using C18 column (linear gradient10-35% acetonitrile in water with 0.1% TFA) to give a yellow solid: MS(Mz+1=569); ¹H NMR (300 MHz, CD₃OD) δ 7.48 (s, 1H), 4.63 (d, 1H, J=8.9Hz), 4.57 (d, 1H, J=8.9 Hz), 4.12 (d, 1H, J=0.9 Hz), 3.10-2.96 (9H),2.50 (m, 1H), 2.22 (s, 3H), 2.18 (m, 1H), 1.62 (m, 1H). Compounds M andR were also prepared in a similar manner and compound BE may also beprepared in a similar manner.

(4S,4aS,5aR,12aS)-4-Dimethylamino-7-(ethoxyamino-methyl)-3,10,12,12a-tetrahydroxy-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydro-naphthacene-2-carboxylicacid amide (Compound AA)

An amount of 7-formyl-sancycline (1.5 g, 3.39 mmol) was combined withmethanol (30 mL) and O-(ethoxy)methylamine (1.5 g, 15.5 mmol) and wasstirred at room temperature under a blanket of argon. The reaction wasmonitored by HPLC and LC/MS, which indicated that the reaction wascomplete in about 3 hours. The solvent was evaporated in vacuo and theresulting yellow solid was dried. A yellow solid (2.3 g) was isolated asan oxime. LC/MS: (m/z+1) 485.

The oxime (2.3 g, 4.72 mmol) was suspended in methanol saturated withHCl (45 mL) and cooled in an ice bath. An amount of NaCNBH₃ (585 mg,9.44 mmol) was added in small batches followed by a few drops ofmethanol saturated with HCl via syringe. The reducing agent was addedover the course of about two hours. The reaction was monitored by HPLCand LC/MS and was complete within 2 hours. The solvent was evaporated invacuo and was purified in 5 batches on preparatory HPLC using C18 column(linear gradient 10-45% acetonitrile in 20 mM aqueous triethanolamine,pH 7.4).

The purified compound was dried in vacuo and redissolved in methanol (20mL) saturated with HCl to exchange the salt. The compound was driedovernight over P₂O₅ to yield the product (0.21 mg, 13%) as a yellowpowder. ESI-MS: (MH+)=488. ¹H NMR (300 MHz, CD₃OD) δ 7.63 (1H, d, J=9Hz), 6.93 (1H, d, J=9 Hz), 4.53 (s, 1H), 4.17 (m, 3H), 3.25 (m, 1H),3.07 (m, 8H), 2.44 (m, 1H), 2.31 (m, 1H), 1.62 (m, 1H), 1.29 (3H, t, J=7Hz). Compounds AM, AB, AE, AR, AS, AT, AU, AY, AF and AX were alsoprepared in a similar manner and compounds AG, BA, BB, BC and BD may beprepared in a similar manner.

(4S,4aS,5aR,12aS)-4-Dimethylamino-3,10,12,12a-tetrahydroxy-7-(isopropoxyamino-methyl)-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydro-naphthacene-2-carboxylicacid amide (Compound AN)

A solution of 7-formylsancycline (1.8 mmol) and O-isopropylhydroxylaminehydrochloride (9 mmol) in methanol (25 mL) was stirred overnight. Thesolvent was reduced and the crude product was used for the next reactionwithout further purification. A solution of7-(isopropoxyimino-methyl)-sancycline (2 mmol) in methanol saturatedwith HCl was cooled in an ice-bath and NaCNBH₃ was added portion-wisewhile stirring at the same temperature. The solvent was reduced and thecrude product was purified by prep-HPLC using C18 column (lineargradient 15-30% acetonitrile in 20 mM aqueous triethanolamine, pH 7.4)to give a yellow solid: MS (Mz+1=502); ¹H NMR (300 MHz, CD₃OD) δ 7.63(d, 1H, J=8.7 Hz), 6.92 (d, 1H, J=8.7 Hz), 4.44 (m, 1H), 4.14 (d, 1H,J=1.2 Hz), 3.27-2.97 (9H), 2.43 (t, 1H, J=14.4), 2.27 (m, 1H), 1.29 (m,6H). Compounds AM, AB, AE, AR, AS, AT, AU, AY, AF and AX were preparedin a similar manner and compounds AG, BA, BB, BC and BD may be preparedin a similar manner.

(4S,4aS,5aR,12aS)-4-Dimethylamino-7-[(2-fluoro-ethoxyamino)-methyl]-3,10,12,12a-tetrahydroxy-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydro-naphthacene-2-carboxylicacid amide (Compound AO)

A solution of 7-formylsancycline (4 mmol) and 2-fluoroethylhydroxylaminehydrochloride (10 mmol) in methanol (50 mL) was stirred overnight, afterwhich LC-MS showed completion of the reaction. The methanol was reducedand the crude product was used for the next reaction without furtherpurification. To a cooled solution of7-(2′-fluoro-ethoxyimino-methyl)-sancycline (2 mmol) in methanolsaturated with HCl was added portion-wise NaCNBH₃ (8 mmol) over 8 hourswhile stirring at the same temperature. The solvent was reduced and thecrude product was purified by prep-HPLC using C18 column (lineargradient 10-40% acetonitrile in 20 mM aqueous triethanolamine, pH 7.4)to give a yellow solid: MS (Mz+1=506); ¹H NMR (300 MHz, CD₃OD) δ 7.65(d, 1H, J=8.8 Hz), 6.93 (d, 1H, J=8.8 Hz), 4.75 (m, 1H), 4.61-4.55 (3H),4.46 (m, 1H), 4.36 (m, 1H), 4.16 (d, 1H, J=1.2 Hz), 3.26-2.97 (9H), 2.45(t, 1H, J=14.4), 2.31 (m, 1H), 1.63 (m, 1H). Compounds AM, AB, AE, AR,AS, AT, AU, AY, AF and AX were prepared in a similar manner andcompounds AG, BA, BB, BC and BD may be prepared in a similar manner.

4S,4aS,5aR,12aS)-4-Dimethylamino-3,10,12,12a-tetrahydroxy-7-(3-imino-isoxazolidin-2-ylmethyl)-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydro-naphthacene-2-carboxylicacid amide (Compound AZ)

A solution of 7-formylsancycline (2 mmol) and 3-aminooxy-propiononitrile(4 mmol) in methanol (30 mL) was stirred overnight. The solvent wasreduced and the crude product was used for the next reaction withoutfurther purification. A solution of7-(2′-cyanoethoxyimmuno-methyl)-sancycline in methanol with HCl wascooled with an ice-bath. An amount of NaCNBH₃ was added portion-wise andstirred for 1.5 hours. The solvent was evaporated and purified byprep-HPLC using C-18 column (linear gradient 10-40% acetonitrile in 20mM aqueous triethanolamine, pH 7.4) to give a yellow solid: MS(Mz+1=513); ¹H NMR (300 MHz, CD₃OD) δ 7.47 (d, 1H, J=8.8 Hz), 6.86 (d,1H, J=8.8 Hz), 5.11 (d, 1H, J=15.9 Hz), 4.96 (d, 1H, J=15.9 Hz), 4.41(m, 2H), 4.11 (s, 1H), 3.50 (t, 2H, J=8.4 Hz), 3.20-2.94 (9H), 2.38 (t,1H, J=15.3 Hz), 2.28 (m, 1H), 1.60 (m, 1H). Compounds AM, AB, AE, AR,AS, AT, AU, AY, AF and AX were prepared in a similar manner andcompounds AG, BA, BB, BC and BD may be prepared in a similar manner.

(4S,4aS,5aR,12aS)-4-Dimethylamino-3,12,12a-trihydroxy-1,11-dioxo-7-pyrazin-2-yl-1,4,4a,5,5a,6,11,12a-octahydro-naphthacene-2-carboxylicacid amide (Compound W)

An amount of 7-iodo-sancycline (1 g, 1.53 mmol) was combined with CuI(0.029 g, 0.153 mmol), Pd₂(dba)₃ (0.140 g, 0.153 mmol),tri-2-furylphosphine (0.284 g, 0.153 mmol), 2-tributylstannylpyrazine(0.677 g, 0.184 mmol), and DMF (6 mL) in a 20 mL glass microwave vial.The reaction mixture was placed in the microwave for 10 minutes at 100°C. on high absorbance. The solvent was evaporated in vacuo. Thefree-base of the this compound was made by pouring 8 g of product into1.8 L water (0.1% TFA). To the resulting heterogeneous mixture, celitewas added and the material was filtered through a celite plug. The waterfiltrate was loaded onto a prepared DVB column, and washed with water(0.1% TFA) and 0.25 M NaOAc until a basic pH of the eluent was obtained.The DVB column was then washed with distilled water until a neutral pHwas obtained and the compound was then eluted as the free-base withCH₃CN.

An amount of 7-pyrazine-sancycline-free base (1 g, 0.209 mmol) wascombined with dry THF (15 mL) in a 100 mL 2 neck round bottom flask. Thereaction solution was cooled in an ice bath under a blanket of argon andpotassium t-butoxide (1.17 g, 1.04 mmol) was added in one portion. Theresulting heterogeneous mixture was stirred in an ice bath for 45minutes. To this was added N-phenylbis-(trifluoromethanesulfonamide)(1.49 g, 4.18 mmol) in one portion. The resulting homogeneous solutionwas stirred in an ice bath for 45 minutes, then warmed to roomtemperature and reaction solution was stirred for another 1 hour. Thereaction mixture was poured into 200 mL 0.5 M HCl, celite was added, andthe mixture was filtered through a celite plug. The water filtrate wasloaded onto a prepared DVB column, washed with 0.5 M HCl, water, theneluted product with CH₃CN (0.1% TFA). The product was evaporated todryness and purified on a prep-HPLC using C-18 column. Clean fractionswere evaporated to dryness.

An amount 7-pyrazine-10-triflate-sancycline (0.220 g, 0.352 mmol) wascombined with ammonium formate (0.112 g, 1.77 mmol), lithium chloride(0.074 g, 1.77 mmol), Pd₂(dppf)₂Cl₂ (0.052 g, 0.071 mmol), DMA (1.5 mL),and water (1.5 mL) in a glass microwave vial. The reaction mixture waspurged with argon and placed in microwave for 10 minutes at 100° C. onhigh absorbance. The reaction solution was poured into 100 mL water(0.1% TFA), and filtered through celite. The resulting yellow eluent wasloaded onto a prepared 2 g DVB cartridge and eluted with CH₃CN (0.1%TFA). The solvent was evaporated and purified on a prep-HPLC using C18column (linear gradient 5-45% acetonitrile in water with 0.1% TFA). Thepurified compound was dried in vacuo and re-dissolved in methanol (20mL) saturated with HCl to exchange the salt. The compound was driedovernight over P₂O₅ to yield the product (0.035 g, 16%) as a yellowpowder. ESI-MS: (MH+)=477. ¹H NMR (300 MHz, CD₃OD) δ 8.77 (m, 1H), 8.71(m, 1H), 8.63 (m, 1H), 8.14 (m, 1H), 7.71 (m, 1H), 7.57 (m, 1H), 3.99(m, 1H), 2.97 (m, 9H), 2.63 (m, 1H), 2.04 (m, 1H), 1.62 (m, 1H)Compounds D, E, F, G and S were also prepared in a similar manner.

(4S,4aS,5aR,12aS)-4-Dimethylamino-3,10,12,12a-tetrahydroxy-1,11-dioxo-7-(1H-pyrrol-2-yl)-1,4,4a,5,5a,6,11,12a-octahydro-naphthacene-2-carboxylicacid amide (Compound T)

An amount of 7-iodo-sancycline (1 g, 1.53 mmol) was combined withPd(OAc)₂ (0.034 g, 0.153 mmol), methanol (1 mL), and DMF (2 mL) in aglass microwave vial. The reaction mixture was purged with argon and anamount of Na₂CO₃ (0.482 g, 4.59 mmol) dissolved in water (1 mL) wasadded by syringe into reaction vessel resulting in a heterogeneousmixture. An amount of 1-N-Boc-pyrrole-2-boronic acid (0.645 g, 3.06mmol) was dissolved in DMF (1 mL) and was added by syringe into thereaction vessel. The resulting mixture was microwaved for 10 minutes at100° C. On completion of the reaction, the mixture was filtered throughcelite and the solvent was reduced in vacuo. The crude reaction mixturewas then triturated with 500 mL diethyl ether to yield a yellowprecipitate. The precipitate was filtered, rinsed with fresh diethylether, and dried under vacuum to yield 700 mg of yellow solid. Thisyellow material was then added to TFA (10 mL) and stirred at roomtemperature for 5 minutes. The solvent was reduced and the crude productwas purified by prep-HPLC using C18 column (linear gradient 15-50%acetonitrile in water with 0.1% TFA). The purified compound was dried invacuo and redissolved in methanol (20 mL) saturated with HCl to exchangethe salt. The compound was dried overnight over P₂O₅ to yield theproduct (0.020 g, 3%) as a yellow powder. ESI-MS: (MH+)=480. ¹H NMR (300MHz, CD₃OD) δ 7.53 (1H, d, J=9 Hz), 6.87 (1H, d, J=9 Hz), 6.80 (m, 1H),6.16 (m, 1H), 6.08 (m, 1H), 4.06 (s, 1H), 3.18 (m, 1H), 2.98 (m, 9H),2.49 (m, 1H), 2.09 (m, 1H), 1.61 (m, 1H). Compounds J, K and L were alsoprepared in a similar manner.

(4R,4aS,5aR,12aS)-4-Dimethylamino-7-(3-dimethylamino-1-ethoxyimino-propyl)-3,10,12,12a-tetrahydroxy-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydro-naphthacene-2-carboxylicacid amide (Compound I)

A mixture of 7-iodosancycline (5 mmol), (O-tolyl)₃P (1 mmol), Pd(PPh₃)₄(1 mmol), Pd(OAc)₂ (1 mmol), CuI (1 mmol]) and triethylamine inacetonitrile (45 mL) was purged with argon. An amount of1-N,N-dimethylamino-2-propyne was added and the reaction mixture wasslowly (˜40 minutes) warmed up to 50° C. The reaction mixture was thenpoured into 1 L of 0.1% TFA in water and filtered through a celite pad.The filtrate was taken and water was removed using short column of DVB.The crude product was used for the next reaction without furtherpurification.

An amount of 7-(3′-dimethylamino)-prop-1-ynyl-sancycline (the crudeproduct from the above reaction) was dissolved in a cooled H₂SO₄solution (conc H₂SO₄:H₂O, 4/1, 35 mL) at an ice-bath temperature. Thereaction mixture was stirred for 5 minutes and was poured into acidicwater (0.1% TFA, 1 L). The resulting solution was then filtered throughcelite pad and water was removed using short column of DVB. The compoundwas purified by prep-HPLC using C18 column (linear gradient 5-30%acetonitrile in water with 0.1% TFA).

A solution of 7-(3′-dimethylamino-propionyl)-sancycline (5.12 mmol) andO-ethoxylamine hydrochloride (41 mmol) in N,N-dimethylacetamide wasstirred at 80° C. under microwave conditions for 70 minutes. The productwas purified by prep-HPLC using C18 column (linear gradient 10-40%acetonitrile in water with 0.1% TFA) to give a yellow solid: MS(Mz+1=557); ¹H NMR (300 MHz, CD₃OD) δ 7.39 (m, 1H), 6.91 (m, 1H), 4.86(1H, d, J=3.9 Hz), 4.26-4.08 (m, 2H), 3.5 (m, 1H), 3.30-2.87 (18H), 2.50(m, 1H), 2.20 (m, 1H), 1.56 (m, 1H), 1.36-1.19 (m, 3H). Compound O wasalso prepared in a similar manner.

(4S,4aS,5aR,12aS)-4-Dimethylamino-3,10,12,12a-tetrahydroxy-1,11-dioxo-7-(pyrrol-1-yliminomethyl)-1,4,4a,5,5a,6,11,12a-octahydro-naphthacene-2-carboxylicacid amide (Compound AC)

An amount of 7-formyl sancycline (0.4 g, 0.905 mmol) was combined with1-aminopyrrole (0.223 g, 2.71 mmol) and DMA (8 mL) in a glass vial. Thereaction mixture was stirred at room temperature under a blanket ofargon for 30 minutes. The crude reaction mixture was poured into water(0.1% TFA) (100 mL) and loaded onto a prepared 5 g DVB cartridge, whichwas then washed with water and eluted with CH₃CN (0.1% TFA). Afterevaporating the volatiles, the resulting compound was purified byprep-HPLC using C18 column (linear gradient 10-70% acetonitrile in 20 mMaqueous triethanolamine, pH 7.4). The purified compound was dried invacuo and redissolved in methanol (20 mL) saturated with HCl to exchangethe salt. The compound was dried overnight over P₂O₅ to yield theproduct (0.035 g, 8%) as a yellow powder. ESI-MS: (MH+)=507. ¹H NMR (300MHz, CD₃OD) δ 8.78 (s, 1H), 8.12 (1H, d, J=9 Hz), 7.23 (2H, t, J=3 Hz),6.93 (1H, d, J=9 Hz), 6.17 (2H, t, J=3 Hz), 4.08 (s, 1H), 3.54 (m, 1H),2.97 (m, 9H), 2.47 (m, 1H), 2.24 (m, 1H), 1.65 (m, 1H). Compound X wasalso prepared in a similar manner.

(4S,4aS,5aR,12aS)-7-(N,N″-Diethyl-hydrazinomethyl)-4-dimethylamino-3,10,12,12a-tetrahydroxy-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydro-naphthacene-2-carboxylicacid amide (Compound Z)

An amount of 7-formyl sancycline (0.5 g, 1.13 mmol) was combined with1,2-dimethylhydrazine (0.546 g, 3.39 mmol), triethylamine (0.472 g, 3.39mmol), and DMA (10 mL) in a glass vial. The resulting heterogeneousmixture was stirred at room temperature under a blanket of argon for 45minutes. An amount of NaCNBH₃ (0.084 g, 1.36 mmol) was added to thereaction mixture and stirred overnight at room temperature. The reactionmixture was poured into water (0.1% TFA), loaded onto a prepared 5 g DVBcartridge, and eluted with CH₃CN (0.1% TFA). After evaporatingvolatiles, the crude product was purified on a prep-HPLC using C18column (linear gradient 5-60% acetonitrile in 20 mM aqueoustriethanolamine, pH 7.4). The purified compound was dried in vacuo andredissolved in methanol (20 mL) saturated with HCl to exchange the salt.The compound was dried overnight over P₂O₅ to yield the product (0.030g, 6%) as a yellow powder. ESI-MS: (MH+)=515. ¹H NMR (300 MHz, CD₃OD) δ7.53 (1H, d, J=9 Hz), 6.87 (1H, d, J=9 Hz), 4.18 (m, 1H), 4.06 (s, 2H),3.19 (m, 1H), 3.00 (m, 10H), 2.40 (m, 1H), 2.20 (m, 1H), 1.64 (m, 1H),1.24 (3H, t, J=9 Hz), 1.13 (m, 3H).

Allyl-((6aS,10S,10aS,11aR)-8-carbamoyl-10-dimethylamino-4,6,6a,9-tetrahydroxy-5,7-dioxo-5,6a,7,10,10a,11,11a,12-octahydro-naphthacen-1-ylmethyl)-carbamicacid methyl ester (Compound F)

A solution of 7-formylsancycline (1.5 mmol) and allylamine (4.5 mmol) in1,2-dichloroethane (50 mL) was stirred for 30 minutes. Sodiumtriacetoxyborohydride was added and stirred for an additional 3 hours.The solvent and excess reagent were evaporated and the crude materialwas purified by prep-HPLC to give 7-alkylaminomethyl-sancycline as ayellow solid: MS (Mz+1=484).

To a solution of 7-allylaminomethyl-sancycline (0.78 mmol) inN,N-dimethylacetamide (7 mL) was added methylchloroformate (1.6 mmol)dropwise and the reaction mixture was stirred for 1 hour. An additionalamount of methylchloroformate (1.6 mmol) was added and stirred foradditional 3 hours. The resulting product was purified by prep-HPLCusing C18 column (linear gradient 15-30% acetonitrile in water with 0.2%formic acid) to give a yellow solid: MS (Mz+1=542); ¹H NMR (300 MHz,CD₃OD) δ 7.34 (1H, d, J=8.5 Hz), 6.82 (1H, d, J=8.5 Hz), 5.71 (m, 1H),5.06 (m, 2H), 4.47 (m, 2H), 4.08 (1H, d, J=0.9 Hz), 3.84-3.65 (m, 2H),3.71 (s, 3H), 3.21-2.92 (9H), 2.30-1.94 (2H), 1.59 (m, 1H).

(4S,4aS,5aR,12aS)-4,7-Bis-dimethylamino-3,10,12,12a-tetrahydroxy-9-(methoxyimino-methyl)-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydro-naphthacene-2-carboxylicacid amide (Compound V)

A solution of 9-formylminocycline (1.19 mmol) and O-methyldroxylaminehydrochloride (5.96 mmol) in methanol (15 mL) was stirred for 1.5 hours.The solvent was evaporated and purified by prep-HPLC using C18 column(linear gradient 10-50% acetonitrile in 20 mM aqueous triethanolamine,pH 7.4) to give a yellow solid: MS (Mz+1=515); ¹H NMR (300 MHz, CD₃OD) δ8.42 (s, 1H), 8.09 (s, 1H), 4.13 (1H, d, J=1.2 Hz), 3.99 (s, 3H), 3.35(m, 1H), 3.09-2.98 (14H), 2.43 (m, 1H), 2.24 (m, 1H), 1.69 (m, 1H).Compounds AK and AH may also be prepared in a similar manner.

(4S,4aS,5aR,12aS)-4-Dimethylamino-3,10,12,12a-tetrahydroxy-7-(2-methylamino-3,4-dioxo-cyclobut-1-enyl)-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydro-naphthacene-2-carboxylicacid amide (Compound AD)

A mixture of 7-iodosancycline (2 mmol),3-isopropoxy-4-tributylstannanyl-cyclobut-3-ene-1,2-dione (4.4 mmol),tetrakis(triphenylphosphine)palladium (0.4 mmol) and CuI (0.4 mmol) inN,N-dimethylacetamide was microwave irradiated for 50 minutes at 80° C.The resulting compound was purified using a DVB column to give7-(2′-isopropoxy-3′,4′-dioxo-cyclobut-1′-enyl)-sancycline as a yellowsolid: MS (Mz+1=553).

To a solution of7-(2′-isopropoxy-3′,4′-dioxo-cyclobut-1′-enyl)-sancycline (0.9 mmol) inmethanol (20 mL) was added 1 mL of 33% methylamine in absolute ethanoland the reaction mixture was stirred for 40 minutes. The resultingproduct was purified by prep-HPLC using C18 (linear gradient 10-40%acetonitrile in 20 mM aqueous triethanolamine, pH 7.4) column to give ayellow solid: MS (Mz+1=524); ¹H NMR (300 MHz, CD₃OD) δ 7.46 (1H, d,J=8.7 Hz), 6.88 (1H, d, J=8.7 Hz), 4.01 (s, 1H), 3.27 (s, 3H), 3.07-2.82(9H), 2.45 (m, 1H), 2.10 (m, 1H), 1.52 (m, 1H). Compounds AI and AJ mayalso be prepared in a similar manner.

(4S,4aS,5aR,12aS)-4-Dimethylamino-7-{[(2-ethoxyimino-propyl)-methyl-amino]-methyl}-3,10,12,12a-tetrahydroxy-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydro-naphthacene-2-carboxylicacid amide (Compound AL)

A solution of 7-formylsancycline (2 mmol) andmethyl-(2-methyl-[1,3]dioxolan-2-ylmethyl)-amine (6 mmol) inN,N-dimethylformamide (30 mL) was stirred for 40 minutes. Sodiumtriacetoxyborohydride (6 mmol) was added and the reaction was stirredfor 6 hours. The solvent was evaporated and the crude material wasdissolved in a mixture of tetrahydrofuran (10 mL), acetic acid (10 mL)and 6M HCl (10 mL). This solution was stirred at 60° C. for 6 hours.Upon completion, the solvent and excess reagents were evaporated and thecrude material was purified by prep-HPLC to give7-{[(methyl-2′-oxo-propyl)-methyl-amino]-methyl}-sancycline as a yellowsolid: MS (Mz+1=514).

A solution of7-{[(methyl-2′-oxo-propyl)-methyl-amino]-methyl}-sancycline (0.63 mmol)and O-ethylhydroxyamine hydrochloride (3.15 mmol) in methanol (15 mL)was stirred for 8 hours. The solvent was evaporated and purified byprep-HPLC using C18 column (linear gradient 20-50% acetonitrile in 20 mMaqueous triethanolamine, pH 7.4) to give a yellow solid: MS (Mz+1=599);¹H NMR (300 MHz, CD₃OD) δ 7.69 (1H, d, J=8.7 Hz), 6.99 (1H, d, J=8.7Hz), 4.65 (m, 1H), 4.35 (m, 1H), 4.24 (2H, q, J=7.1 Hz), 4.15 (s, 1H),4.07 (brs, 2H), 3.24-2.85 (12H), 2.50 (m, 1H), 2.30 (m, 1H), 1.95 (s,3H), 1.52 (m, 1H), 1.31 (3H, t, J=7.1 Hz).

(4S,4aS,5aR,12aS)-4-Dimethylamino-9-[(methoxy-methyl-amino)-methyl-3,10,12,12a-tetrahydroxy-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydro-naphthacene-2-carboxylicacid amide (Compound AP)

An amount of 7-bromo-9-formyl-sancycline (1.92 mmol) was combined withN,O-dimethyl-hydroxylamine HCl salt (3.84 mmol) and DMA (8 mL) andstirred under an argon atmosphere at room temperature for 1.5 hours. Anamount of sodium cyanoborohydride (2.3 mmol) was added and the reactionwas monitored by LC/MS. The reaction mixture was triturated in diethylether (300 mL), and filtered to give 1.3 g of7-bromo-9-methoxyaminomethyl sancycline.

An amount of 7-bromo-9-methoxyaminomethyl sancycline (0.88 mmol) wascombined with ammonium formate (8.83 mmol), Pd(dppf)₂CH₂Cl₂ (0.0883mmol), InCl₃ (0.442 mmol), and NMP (7 mL) in a microwave vial and placedin the microwave on high absorbance for 5 minutes at 100° C. Thereaction mixture was poured into water (400 mL with 0.1% TFA) and wasfiltered through celite. The crude product was purified by prep-HPLCusing a C-18 column (linear gradient 10-40% acetonitrile in water with0.1% TFA). ESI-MS: (MH+)=488. ¹H NMR (300 MHz, CD₃OD) δ 7.64 (1H, d, J=9Hz), 6.90 (1H, d, J=6 Hz), 4.67 (m, 2H), 4.11 (s, 1H), 3.98 (m, 3H),3.17 (m, 4H), 2.97 (m, 9H), 2.61 (m, 1H), 2.23 (m, 1H), 1.61 (m, 1H).

Example 2 Anti-Bacterial Activity

In this example, the gram (+) and gram (−) antibacterial activities ofthe tetracycline compounds used in the methods of the invention wereassessed.

Gram (−) and gram (+) antibacterial minimum inhibitory concentration(MIC) values (μg/mL) were obtained using CLSI methodology foranti-bacterial susceptibility testing. On each day of testing, serialdilutions of compounds were prepared in microdilution plates using aTecan robotic workstation. Mueller Hinton broth cultures ofrepresentative sensitive and resistant gram negative strains were grownor adjusted to match the turbidity of a 0.5 McFarland standard. 1:200dilutions were made in an appropriate broth (cation supplemented MuellerHinton broth) to allow a final inoculum of 1×10⁵ cfu. Plates wereincubated at 35° C. in ambient air for 18-24 hours, were readspectrophotometrically and checked manually for evidence of bacterialgrowth. The lowest dilution of compound that inhibited growth wasrecorded as the MIC. Lysed horse blood was used to supplement broth fortesting S. pneumoniae. The MIC's for each compound were assessed againstS. aureus, S. pneumoniae, P. acnes, E. coli and B. theta. The resultsare shown in Table 3. Good antibacterial activity (e.g., less than about4 μg/mL) is indicated by “***,” modest antibacterial activity (betweenabout 4 and 8 μg/mL) is indicated by “**,” or weak antibacterialactivity (greater than about 8 μg/mL) is indicated by “*.” The symbol“−” indicates that no data was obtained.

TABLE 3 Compound S. aureus S. pneumoniae P. acnes P. acnes B.thetaiotaomicron Code RN450 157E - Strep ATCC 6919 ATCC 11827 E. coliATCC 25922 E. coli MG 1655 ATCC 29741 A *** *** *** *** *** ** * B ****** *** *** * * ** C *** *** *** *** * * * D *** *** ** ** * * * E ****** *** *** ** * * F *** *** *** *** * * ** G *** *** ** ** ** * * H ****** ** ** * * * I *** *** *** *** *** *** ** J *** *** *** *** *** ****** K *** *** *** *** *** *** *** L *** *** *** *** *** *** *** M ****** *** *** *** ** ** N *** *** *** *** *** ** *** O *** *** *** *** ****** *** P *** *** *** *** ** ** ** Q *** *** *** *** ** ** ** R *** ****** *** * * ** S *** *** ** ** * * * T *** *** *** *** *** *** ** U ****** *** *** *** ** ** V *** *** *** *** * * ** W *** *** *** *** * * * X*** *** *** *** *** *** *** Y *** ** *** *** * * * Z *** *** *** *** **** * AA *** *** *** *** ** ** ** AB *** *** *** *** ** * ** AC *** ****** *** ** * ** AD *** *** *** *** ** ** * AE *** *** *** *** ** * ** AF*** *** *** *** ** ** *** AL *** *** *** *** ** ** ** AM ** ** ****** * * ** AN *** *** *** *** ** * ** AO *** *** *** *** *** * ** AP **** ** ** * * ** AQ *** *** *** ** * * ** AR *** *** *** *** ** ** *** AS*** ** *** *** * * ** AT *** *** *** *** ** * *** AU *** ** *** *** * *** AV *** *** *** *** ** * ** AW *** *** *** *** ** ** ** AX *** *** ****** ** ** *** AY *** ** *** *** * * ** AZ *** *** — — * * — Doxycycline*** *** *** *** *** *** ** Minocycline *** *** *** *** *** *** **

Example 3 Toxicity Profile

In this example, the cytotoxicity of the tetracycline compounds used inthe methods of the invention were assessed.

Mammalian cell cytotoxicity was assessed to evaluate potential in vivorisks associated with the tetracycline compounds of the invention. Asoluble, non-toxic redox dye (“Resazurin”; Alamar Blue) was used toassess a tetracycline compound's effect on cellular metabolism. At theonset of the experiment, cultures of mammalian COS-1 or CHO cells werewashed, trypsinized, and harvested. Cell suspensions were prepared,seeded into 96-well black-walled microtiter plates, and incubatedovernight at 37° C., in 5% CO₂ and approximately 95% humidity. On thenext day, serial dilutions of test drug were prepared under sterileconditions and transferred to cell plates. Plates were then incubatedunder the above conditions for 24 hours. Following the incubationperiod, the media/drug was aspirated, and 50 μL of resazurin was added.Plates were then incubated under the above conditions for 2 hours andthen in the dark at room temperature for an additional 30 minutes.Fluorescence measurements were taken (excitation 535 nm, emission 590nm) and toxic effects in treated versus control cells were comparedbased on the degree of fluorescence in each well. The results are shownin Table 4. Minocycline and doxycycline toxicity scores are shown forcomparison. Compounds which showed some cytotoxicity (e.g., less thanabout 35 μg/mL) to are indicated by “***,” compounds which showedmoderate cytoxicity are indicated by “**” (e.g., between about 35 and 75μg/mL) and compounds that showed minimal cytoxicity are indicated by “*”(e.g., greater than about 75 μg/mL).

TABLE 4 COS-1 CHO Cytotoxicity Cytotoxicity IC₅₀ IC₅₀ Compound (μg/mL)(μg/mL) Minocycline * * Doxycycline * * A *** *** B *** *** C * * D * *E * * F *** *** G * * H * * I * * J *** *** K *** *** L *** *** M * *N * * O ** *** P * * Q *** *** R *** *** S * * T *** *** U * ** V ****** W * * X *** *** Y * * Z * * AA * * AB *** *** AC *** *** AD *** ***AE * *** AF ** ** AL *** *** AM * * AN *** *** AO * * AP ** ** AQ ****** AR *** ** AS * * AT *** *** AU * * AV ** ** AX *** ***

Example 4 Phototoxic Potential

In this example, the phototoxic potential of the tetracycline compoundsused in the methods of the invention was assessed. In particular, 3T3fibroblast cells were harvested and plated at a concentration of 1×10⁵cells/mL and the plates were incubated overnight at 37° C., in 5% CO₂and approximately 95% humidity. On the following day the medium wasremoved from the plates and replaced with Hanks' Balanced Salt Solution(HBSS). Drug dilutions were made in HBSS and added to the plates. Foreach compound tested, a duplicate plate was prepared that was notexposed to light as a control for compound toxicity. Plates were thenincubated in a dark drawer (for controls), or under UV light (meterreading of 1.6-1.8 mW/cm²) for 50 minutes. Cells were then washed withHBSS, fresh medium was added, and plates were incubated overnight asdescribed above. The following day neutral red was added as an indicatorof cell viability. The plates were then incubated for an additional 3hours. Cells were then washed with HBSS and blotted on absorbent paperto remove excess liquid. A solution of 50% EtOH, 10% glacial acetic acidwas added and after 20 minutes incubation, and the plate's absorbance at535 nm was read using a Wallac Victor 5 spectrophotometer. Thephototoxicity reflected the difference between the light-treated andcontrol cultures. The results are given in Table 5. Results for thetetracycline derivative COL-3, as well doxycycline and minocycline areshown for comparison. Compounds which showed phototoxicity are indicatedby “****” (e.g., less than 5 μg/mL), compounds which showed moderatephototoxicity are indicated by “***” (e.g., greater than about 5 μg/mLand less than about 25 μg/mL), compounds which showed some phototoxicityare indicated by “**” (e.g., greater than about 25 μg/mL and less thanabout 75 μg/mL) and compounds that showed minimal or no phototoxicityare indicated by “*” (e.g., greater than about 75 μg/mL).

TABLE 5 Compound Dark Tox50 UV Tox50 Code (uM) (uM) Minocycline * *Doxycycline * *** COL-3 ** **** A * *** B * * C * ** D * ** E * ** F *** G * ** H * * I * * J * * K * * L * **** M * * N * * O * ** P * **Q * * R * * S * ** T * * U * * V * * W * ** X * *** Y * * Z * * AA * *AB * *** AC * * AD * * AE * ** AF * * AL * *** AM * * AN * ** AO * *AQ * ** AR * ** AS * * AT * *** AU * * AV * * AX * *

Example 5 Half-Life Determination of the Oxidation

In this example, the half-life of minocycline and a tetracyclinecompound used in the methods of the invention were assessed underoxidative conditions, as described in Nilges, et al. (Nilges M, EnochsW, Swartz H. J. Org. Chem. 1991, 56, 5623-30). Not to be limited bytheory, it is believed that the tissue staining may be caused oxidativeinstability. The tetracycline compounds were subjected to acceleratedoxidation in a continuous-flow microreactor using a 15 molar excess ofsodium periodate at pH 11 and 22° C. Aliquots of each reaction mixturewere quenched at various time points with ascorbic acid and thedisappearance of each compound was determined by RP-HPLC. Pseudofirst-order rate constants and t_(1/2) values were obtained from theplots of log(Ao−At/Ao) versus time, where Ao is the HPLC area determinedfor each compound at time=0 and At is the HPLC area at time=t. Theresults indicated that minocycline had a half-life for oxidation of 8.2seconds, while compound B had a half-life for oxidation of 495 seconds.

Example 6 In Vivo Anti-Bacterial Activity with S. aureus Model

In this example, the in vivo anti-bacterial activity of the tetracyclinecompounds used in the methods of the invention were assessed.

Groups of five mice were injected intraperitoneally with a lethal doseof S. aureus RN450 in a medium of mucin. Mice were evaluated at 24 hoursto determine survival. Untreated animals experienced 100% mortality.Subcutaneous treatment with a single dose of minocycline, doxycycline orthe test compound resulted in 100% survival. In some instances, a doseresponse study was performed with the compound such that a PD₅₀ (a doseof compound that protects 50% of the animals) could be calculated. Theresults are shown in Table 6.

TABLE 6 Dose Percent PD50 Compound (mg/kg) Survival (mg/kg) Untreated — 0 (0/5) — Minocycline 5 100 (5/5) 0.72 Doxycycline 5 100 (5/5) 0.13 A 5100 (5/5) — C 5 100 (5/5) — P 5 100 (5/5) 0.13 Q 5 100 (5/5) 0.45 V 1.4 W 1.08 AA 5 100 (5/5) — AD 4.54 AN 1.1  AF 0.23 AO 0.48 AR 0.58 0.58 AT1.11

Example 7 In Vivo Anti-Inflammatory Activity with RatCarrageenan-Induced Paw Edema Inflammatory Model

To assess the anti-inflammatory potential of the tetracycline compoundsused in the methods of the invention, the tetracycline compounds wereassessed in a model of carrageenan induced rat paw inflammation. Themodel used a sub-plantar injection of carrageenan in the rat to inducean inflammatory response. The test compound or saline (control) wasadministered IP 30 minutes before a subplantar injection of carrageenan(1.5 mg/0.1 mL). Paw volume was measured (mm 2) before subplantarinjection and again 3 hours after the injection of carrageenan using aplethysmometer. The results are shown in FIGS. 1 and 2. Significantdifferences as determined by a Kruskal-Wallis One Way ANOVA are notedbetween the inflammation of the untreated controls versus treatedanimals (p=0.5)

FIG. 1 compares the modulation of carregeenan induced inflammation ofdoxycycline with various doses of compound A. Doxycycline exhibited a50% effective concentration (EC₅₀) at approximately 50 mg/kg, whilecompound A exhibited improved activity.

FIG. 2 compares the modulation of carregeenan induced inflammation ofminocycline compared with various doses of compound P. Minocyclineexhibited an EC₅₀ at approximately 50 mg/kg, while compound P exhibitedsimilar or improved activity.

EQUIVALENTS

Those skilled in the art will recognize, or be able to ascertain usingno more than routine experimentation, numerous equivalents to thespecific procedures described herein. Such equivalents are considered tobe within the scope of the present invention and are covered by thefollowing claims. The contents of all references, patents, and patentapplications cited throughout this application are hereby incorporatedby reference. The appropriate components, processes, and methods ofthose patents, applications and other documents may be selected for thepresent invention and embodiments thereof.

The invention claimed is:
 1. A method for treating a subject sufferingfrom an inflammatory skin disorder, comprising administering aneffective amount of a substituted tetracycline compound to said subject,wherein said substituted tetracycline compound is a compound of formulaI:

wherein X is CHC(R¹³Y′Y), CR^(6′)R⁶, C═CR^(6′)R⁶, S, NR⁶, or O; E isNR^(7d)R^(7e) or OR^(7f); R², R^(2′), R^(4′), R^(4a) and R^(4b) are eachindependently hydrogen, alkyl, alkenyl, alkynyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, alkylamino, arylalkyl, aryl, heterocyclic,or heteroaromatic; R³, R¹⁰, R¹¹ and R¹² are each hydrogen; R⁴ isNR^(4a)R^(4b), alkyl, alkenyl, alkynyl, hydroxyl, halogen, or hydrogen;R⁵ and R^(5′) are each independently hydroxyl, hydrogen, thiol,alkanoyl, aroyl, alkaroyl, aryl, heteroaromatic, alkyl, alkenyl,alkynyl, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino,arylalkyl, alkyl carbonyloxy, or aryl carbonyloxy; R⁶ and R^(6′) areeach independently hydrogen, methylene, absent, hydroxyl, halogen,thiol, alkyl, alkenyl, alkynyl, aryl, alkoxy, alkylthio, alkylsulfinyl,alkylsulfonyl, alkylamino, or an arylalkyl; R^(7a) and R^(7b) are eachindependently hydrogen, alkyl, hydroxyl, alkoxy, alkylthio,alkylsulfinyl, alkylsulfonyl, amino, alkylamino, aminoalkyl, acyl, aryl,arylalkyl, alkylcarbonyloxy, or arylcarbonyloxy; R^(7c), R^(7d) andR^(7e) are each independently hydrogen, alkyl, hydroxyl, alkoxy,alkylthio, alkylsulfinyl, alkylsulfonyl, aminoalkyl, acyl, aryl,arylalkyl, alkylcarbonyloxy, or arylcarbonyloxy, or R^(7c) and R^(7d) orR^(7c) and R^(7f) are linked to form a ring; R^(7f) is hydrogen, allyl,alkyl, alkenyl, alkynyl, alkylthio, alkylsulfinyl, alkylsulfonyl, amino,alkylamino, aminoalkyl, acyl, aryl, arylalkyl or R^(7f) and R^(7c) arelinked to form a ring; R⁸ is hydrogen, hydroxyl, halogen, thiol, alkyl,alkenyl, alkynyl, aryl, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl,alkylamino, or an arylalkyl; R⁹ is hydrogen, nitro, alkyl, alkenyl,alkynyl, aryl, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl,arylalkyl, amino, aminoalkyl, amido, arylalkenyl, arylalkynyl,thionitroso, or —(CH₂)₀₋₃(NR^(9c))₀₋₁C(═Z′)ZR^(9a); Z is CR^(9d)R^(9e),S, NR^(9b) or O; Z′ is O, S, or NR^(9f); R^(9a), R^(9b), R^(9c), R^(9d),R^(9e) and R^(9f) are each independently hydrogen, acyl, alkyl, alkenyl,alkynyl, alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino,arylalkyl, aryl, heterocyclic, or heteroaromatic; R¹³ is hydrogen,hydroxy, alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylsulfinyl,alkylsulfonyl, alkylamino, or an arylalkyl; and Y′ and Y are eachindependently hydrogen, halogen, hydroxyl, cyano, sulfhydryl, amino,amido, alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylsulfinyl,alkylsulfonyl, alkylamino, or an arylalkyl, or a pharmaceuticallyacceptable salt thereof; such that said inflammatory skin disorder istreated.
 2. The method of claim 1, wherein X is CR^(6′)R⁶, R⁴ isNR^(4a)R^(4b), R^(4a) and R^(4b) are each alkyl, and R², R^(2′), R³,R^(4′), R⁵, R^(5′), R⁶, R^(6′), R⁸, R⁹, R¹⁰, R¹¹ and R¹² are eachhydrogen.
 3. The method of claim 1, wherein said substitutedtetracycline compound is:

or a pharmaceutically acceptable salt thereof.
 4. The method of claim 1,wherein said substituted tetracycline compound has an MIC less than thatof doxycycline or minocycline for S. aureus, P. acnes or S. pneumoniae.5. The method of claim 4, wherein said substituted tetracycline compoundhas an MIC less than 32 μg/ml for S. aureus, P. acnes or S. pneumoniae.6. The method of claim 1, wherein said substituted tetracycline compoundis administered topically or orally.
 7. The method of claim 2, whereinR^(7a) and R^(7b) are hydrogen.
 8. The method of claim 7, wherein E isOR^(7f).
 9. The method of claim 8, wherein R^(7c) is hydrogen.
 10. Themethod of claim 9, wherein R^(7f) is alkyl.
 11. The method of claim 8,wherein R^(7c) and R^(7f) are linked to form a ring.
 12. The method ofclaim 11, wherein said ring is a 5- or 6-membered ring.
 13. The methodof claim 12, wherein said ring is


14. The method of claim 8, wherein R^(7c) is alkyl.
 15. The method ofclaim 14, wherein said alkyl is methyl.
 16. The method of claim 15,wherein R^(7f) is alkyl.
 17. The method of claim 16, wherein said alkylis methyl or ethyl.
 18. The method of claim 1, wherein said substitutedtetracycline compound is

or a pharmaceutically acceptable salt thereof.
 19. The method of claim1, wherein said substituted tetracycline compound is

or a pharmaceutically acceptable salt thereof.
 20. The method of claim1, wherein said inflammatory skin disorder is acne or rosacea.